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A watershed in the history of cytology and genetics was
the recognition, only two years after the rediscovery of
Mendel’s laws, of the remarkable similarity between the
behaviour of chromosomes during meiosis and what one
would expect of mendelizing factors. The Sutton–Boveri
hypothesis developed from Theodor Boveri’s empirical
evidence for the individuality of the chromosomes and
Walter Stanborough Sutton’s suggestion, in a paper on
spermatogenesis in Brachystola, ‘that the association of
paternal and maternal chromosomes in pairs and their subse-
quent separation during the reducing division…may consti-
tute the physical basis of the Mendelian law of heredity’1.
In the years after 1902, the attention of cytologists was
intensely focused on tracing the stages of meiosis, for the
events leading to germ cell formation were still very
much contested. In 1905, the British cytologists
J. Brentland Farmer and J.E.S. Moore blamed the lack of
a consensus on empirical difficulties. ‘The divergence of
opinion,’ they stated, ‘is largely due to the extreme
difficulty of disentangling the true sequence of the events
that are proceeding in the intricate series of changes that
constitute the mitoses in question.’2Yet, as Alice Baxter
and John Farley have noted, the differing philosophical
assumptions biologists brought to the microscope also
resulted in disagreements about observations.
The behaviour of chromosomes could not simply be observed;
it had to be interpreted, and this interpretation reflected a
scientist’s assumptions about the nature of the hereditary
process and the hereditary material, the nature of animal
and plant development, and the significance of sexual repro-
duction…It was only after the rediscovery of Mendel’s
laws that cytologists came to share a set of common assump-
tions which led them to agree on what they saw under the
microscope and eventually to accept the link between
chromosomes and mendelian factors3.
The core of the dispute often rested on whether a biolo-
gist interpreted cellular phenomena from a preformation-
ist or an epigenetic standpoint.
The ongoing debate over preformation versus epi-
genesis had re-emerged in a new form in the 1890s as a
consequence of August Weismann’s theory of heredity.
Weismann’s particulate theory of heredity, involving the
continuity of the germ plasm and the need for a reduction
division, bolstered preformationist precepts. Those who
accepted the view of the individuality of the chromo-
somes as entities that persisted throughout the life of the
cell also generally accepted a qualitative reduction of
the chromatin mass, and found it easy to regard the
chromosomes as possible bearers of the hereditary fac-
tors, a view labelled neo-preformationism. By contrast,
those who saw chromosomes as impermanent structures
reconstituted anew at each cell division found the link
between Mendel and meiosis much more problematic.
Although they too accepted a reduction division, they
tended to interpret the meiotic figures as representing a
quantitative reduction of the chromatin mass. For these
epigenetically oriented biologists, the manoeuvres of
chromosomes simply depicted a process in overall cell
differentiation. Heredity resulted not from the segre-
gation of qualitatively different material particles but
through the interaction between the chromosomes, the
cytoplasm and, ultimately, the surrounding cells4.
The implications of the 1890s debate for cytology con-
tinued to resonate after the publication of Mendel’s work.
However, new findings altered the theoretical as well as
the empirical terrain and, by the 1910s, the boundaries de-
marcating these alternative perspectives were less clear.
Although many historians have assumed that the pre-
formationist viewpoint prevailed, we shall see that cytolo-
gists between 1900 and 1915 could accept qualitatively
different mendelian factors and yet continue to uphold an
overriding epigenetic approach. They did this by linking
a particulate theory with physiological activity.
0160-9327/99/$ – see front matter © 2001 Elsevier Science Ltd. All rights reserved. PII: S0160-9327(00)01360-0 Endeavour Vol. 25(2) 2001 55
British cell theory on the eve
of genetics
Marsha L. Richmond
Many historians have assumed that the advent of the chromosome theory of heredity and the theory
of the gene settled the old debate over preformation versus epigenesis in favour of preformation. An
analysis of the views of leading British cytologists between 1900 and 1920 indicates that the story is
more complex. Cytologists could accept seemingly preformationist tenets about the hereditary factors
and yet maintain an overall epigenetic view of organism development by assuming that genes interact
dynamically with the cytoplasm and that the cell is influenced by its environment throughout growth
and development.
Marsha L. Richmond
Is Associate Professor of Science and Technology in the Inter-
disciplinary Studies Program at Wayne State University in Detroit.
Her research focuses on topics connected with the rise of experi-
mental biology in Germany and Britain in the late 19th and early
20th centuries. She is currently completing a book on Richard
Goldschmidt and the birth of developmental genetics.
British cytology and genetics circa 1900
Britain provides a particularly good illustration of the
interactions between cytology, mendelism and the debate
over epigenesis versus preformationism. Although not one
of the rediscoverers of Mendel’s work, William Bateson
(1861–1924) became one of mendelism’s most ardent
champions and the head of a vibrant research program in
genetics at Cambridge5. Yet Bateson was a lifelong scep-
tic of the chromosome theory of heredity, an attitude which
contributed to the demise of the mendelian research pro-
gram6. However, members of Bateson’s research circle
were not as sceptical and made important contributions to
the field that became known as cytogenetics.
Also in Britain, there was an avid discussion of neo-
preformationism versus epigenesis in the 1890s following
the publication of a series of English translations of
Weismann’s works. Influenced by Thomas Henry Huxley’s
physiological conception of the cell, there was a promi-
nent epigenetic tradition in British biology7. One leading
biologist who expressed strong opposition to neo-
preformationism was Adam Sedgwick, head of the
Cambridge School of Morphology, who expressed his dis-
sent in a widely publicized 1894 attack on cell theory8.
Fifteen years later, Sedgwick’s student, the protozoologist
and instructor at Imperial College, London, C. Clifford
Dobell (1886–1949), renewed this challenge. ‘The cell
theory,’ Dobell wrote in 1911, ‘must be abolished. It has
had its value in directing attention to the minute structure
of organisms, especially to their nuclei. Now that it has
forced men to regard things as they should be and not as
they are, it has not only ceased to be of value but has
become positively harmful, its harmful effects are
especially well seen in the case of the Protista.’9Dobell
was also sceptical about the direct connection between
genes and hereditary characters, writing as late as 1925
that, ‘For those who believe, from a study of the Metazoa
and Metaphyta, that the chromosomes – any or all of them –
“determine” morphological characters, “bear” hereditary
properties, or constitute “the physical basis of heredity”,
the foregoing facts should afford ample matter for re-
flexion.’10 Dobell’s views were certainly extreme but, as
we shall see, he was not the only cytologist to demur from
the preformationist overtones of the chromosome theory
even after the details of meiosis were worked out.
The response of British cytologists to Mendel
The status of cell theory on the eve of genetics can be
assessed by examining the views of several leading early
20th century British biologists whose contributions to
cytology addressed the connection between mendelism
and meiosis. These include Robert Heath Lock (1879–
1915), R.P. Gregory (d. 1918), Wilfred Eade Agar
(1882–1951), Geoffrey Watkins Smith (1881–1916) and
Leonard Doncaster (1877–1920). In analysing the publi-
cations of these individuals, I have attempted to gauge
their view towards the Sutton–Boveri hypothesis and their
stance on epigenesis or preformation, as seen in their
approach to the cell, chromosomes, hereditary factors and
development.
Cytology circa 1900
In his widely acclaimed examination of Recent Progress
in the Study of Variation, Heredity and Evolution (1906),
the Cambridge geneticist Robert Heath Lock devoted a
chapter to ‘Recent cytology’. Lock stressed the importance
of Boveri’s and Sutton’s studies supporting the individu-
ality of the chromosomes.
This result is of particular interest, because it gives full
corroboration to the suspicion, previously entertained, that
the chromosomes are specially concerned with hereditary
processes – with the building up of particular parts of the
developing organism into shapes which resemble those of
the corresponding parts displayed by other members of
the same species; and it seems further to show that par-
ticular chromosomes may be specially concerned in the
development of particular parts11.
Lock alluded to this connection by drawing attention to
the connection between Mendel and meiosis. Referring
to accompanying diagrams (Figures 1–3), he stated:
Anyone who has succeeded in following the above account
of the behaviour of the supposed particles representing
Mendelian allelomorphs in the cells of a hybrid organism, on
comparing it with the preceding description of the behaviour
56 Endeavour Vol. 25(2) 2001
A
A
a
B
b
b
abA B
Aa
Bb
A
a
B
b
A
a
B
b
aB
A a
Bb
a BA b
Aa
bB
A a
Bb
Figure 1 Diagram depicting chromosome reduction in the
spermatogenesis of animals. Reproduced, with permission,
from Ref. 32.
of chromosomes in the somatic and reducing divisions
respectively, can scarcely fail to be struck by the extraordi-
nary similarity between the two processes. It seems quite
clear that there must be some real connection between the
behaviour of chromosomes as seen microscopically on the
one hand, and the behaviour of allelomorphic characters as
deduced from the results of experiment on the other; and that
the evidence derived from these two forms of study is bound
to be of considerable mutual benefit12.
Lock was not the only student of Bateson to be impressed
by the Sutton–Boveri hypothesis. In 1905, R.P. Gregory
carried out a cytological study of the pollen and chromo-
somes of certain sterile sweet peas that Bateson bred by
self-fertilization. One of the questions Gregory asked was
how the irregularity of spindle formation during meiosis
bears ‘upon our theories of the individuality of chromo-
somes, and their importance in the transmission of segre-
gated characters’. Gregory also pursued a similar cyto-
logical study in Primula13. The cytologist Wilfred Eade
Agar, Bateson’s former research assistant, initiated a
study in 1907 designed to help settle the question of
reduction division by examining meiosis in the curious
South American lungfish Lepidosiren. Agar particularly
focused on ‘the method by which the numerical reduction
of the chromosomes takes place – owing to its importance
in connecting our experimental knowledge of heredity
with the structure and history of the germ-cells’.14 With
regard to how reduction division takes place among paired
chromosomes during synapsis, Agar readily admitted that
he favoured transverse over longitudinal division, based
on theoretical considerations. If transverse division could
be established, he explained,
it would have a possible great significance for theories of
heredity, for it allows of an extremely intimate union of the
chromosomes, during which condition it is conceivable that
an interchange of particles might take place… This would
remove an often expressed difficulty of correlating
Mendelian phenomena with cytological observation, namely,
that the number of independently transmissible allelomorphs
is often certainly much larger than the number of gametic
chromosomes15.
Lock had earlier come to a similar conclusion, influenced
by Hugo de Vries16. This point is of interest given that
T.H. Morgan became a convert to the chromosome theory
after realizing that the ‘crossing-over’of chromosomes sug-
gested by F.A. Janssen’s 1909 study of chiasmatype solved
several discrepancies between cytological phenomena and
breeding data17.
British cytologists were thus well familiar with the
implications that mendelian hybridization experiments
held for their discipline. In Farmer and Moore’s important
1905 paper on meiosis (a term they coined), they noted
that a ‘considerable weight of evidence has accumulated
within recent years that renders it difficult to dissociate
the facts of heredity from an admission of the existence of
discrete particles that are, individually or collectively,
responsible for the appearance of those particular traits
that characterize one organism and separate it from others’.
Like Agar, they rejected the possibility of a fusion of
homologous chromosomes during synapsis, for this view
militated against chromosome individuality and failed to
account for what was expected of segregating mendelian
factors18. However, it would be wrong on this account to
conclude that British cytologists who accepted the
chromosome theory of heredity primarily favoured neo-
preformationism. Epigenetic underpinnings can most
clearly be detected in the writings of biologists who
worked on the problem of sex determination.
Between 1909 and 1914, the Oxford embryologist
G.W. Smith carried out a thorough analysis of the deter-
mination of sex. A student of G.C. Bourne and of W.F.R.
Weldon, Smith published a ten-part series entitled the
Experimental Analysis of Sex that was prompted by his
doctoral study of ‘artificial castration’ in spider crabs
infected by the parasitic cirripede Sacculina. In the first
paper, entitled On Mendelian Theories of Sex, Smith
acknowledged the ‘very profound influence on contem-
porary biological conceptions’ occasioned by the rediscov-
ery of Mendel’s laws of heredity, and he drew attention to
the mendelian scheme he proposed in 1906 to account for
the heredity of sex in crabs, christened the ‘half-hybrid
theory of sex’. Smith posited two kinds of spermatozoa
representing ‘the male and female sex respectively’ and
assumed that ‘the eggs are purely female’, a scheme that
yielded the observed 1:1 ratio of males to females. Yet the
discovery that male crabs parasitized by Sacculina be-
come hermaphrodites, assuming ‘in various degrees the
secondary sexual characters proper to the female’, led
him to develop a more labile conception of sex determi-
nation, claiming that ‘sex is not necessarily a simple unit
character, inherited in its entirety as such’.19 Rather, Smith
proposed ‘the existence of a sexual formative substance,
Endeavour Vol. 25(2) 2001 57
Figure 2 Depiction of the longitudinal hypothesis of
reduction division, with the two differently shaded parental
chromosomes conjugated side by side. Reproduced, with
permission, from Ref. 33.
Figure 3 Diagram tracing the presumed behaviour of two
different alleles in a mendelian hybrid cross. Reproduced,
with permission, from Ref. 34.
male or female, which controls the development of both
primary and secondary sexual characters’, and he sug-
gested that ‘the male and female modifications of this
substance are the allelomorphs which segregate… and
give rise to the half-hybrid nature of sex.’20
Smith was fully cognizant of the implications that this
view held for the debate over epigenesis versus pre-
formation. Indeed, he believed that his theory provided a
synthesis: ‘the particular problem of sex as being perhaps
determined primarily by the presence or absence in the
germ cells of particular structural elements but being also
partly a question of metabolism, exhibits the same
sympathetic grasp of the just claims of both epigenetic
and evolutionary [that is, preformationist] ideas in
embryological theory’21. His later studies were devoted to
providing empirical support for his views22.
Leonard Doncaster’s work, however, perhaps best illus-
trates the mutually beneficial early relationship between
mendelism and cytology. Like Lock and Agar, Doncaster
was associated with Bateson while a student at Cambridge,
and he subsequently became a central contributor to the
mendelian research program23. Having begun his career
shortly after the rediscovery of Mendel, Doncaster de-
voted much of his scientific career to investigating the
cytological basis of mendelian heredity and can thus be
regarded as an early contributor to cytogenetics24.
Before 1900, cytologists had primarily studied the
chromosomes of pure-bred organisms; after the redis-
covery of Mendel’s laws, they began investigating germ-
cell formation in hybrids and meiosis in parthenogenetic
species in the hope of identifying a physical basis for the
observed hereditary patterns. Doncaster did both. Follow-
ing gametogenesis and fertilization in parthenogenetic
sawflies, he found that the eggs of both ‘virgin and im-
pregnated females’ underwent a reduction division but
that unfertilized, reduced eggs were not viable, develop-
ing only ‘as far as the blastoderm stage’25.
He discovered in 1906 that, in hybrid crosses between
Abraxas grossulariata females and Abraxas lacticolor
males, only A. grossulariata males and A. lacticolor fe-
males resulted, not males and females of both forms – the
first clear case of sex-linked heredity. He followed up by
studying oogenesis and spermatogenesis in Abraxas to
uncover the cytological basis for this unusual outcome.
By 1913, he had been rewarded. He found that the fe-
males of a unisexual family had only 55 chromosomes
instead of the 56 present in wild-type A. grossulariata.
The ‘missing chromosome’ appeared not only to be con-
nected with the A. grossulariata factor but also with sex
determination. ‘It is tempting also to suggest,’ he noted,
‘that this chromosome is a sex-determiner – that if it is
received from the mother and a corresponding one from
the father, the zygote becomes a male, and if it is received
from the father only, it becomes a female.’26
In his next article, however, Doncaster backed away from
a purely morphological explanation of sex. Reviewing the
current knowledge of Chromosomes, Heredity and Sex,
Doncaster acknowledged his complete acceptance of the
chromosome theory of heredity yet, like Smith, whose
work on sex determination he cited, he tempered a purely
morphological explanation with a physiological control
mechanism. His views are most clear when he describes
how such a ‘determinant’ for sex might function.
The general conclusion must be that although the observations
connecting a particular chromosome with the determination of
one sex are in many cases indisputable, there is no evidence
to show how this chromosome acts; and that, since the sex of
the offspring is in some cases modifiable by environment, it is
probable that the presence of the chromosome is associated
with a particular kind of cell-metabolism, of which sex is to
be regarded rather as a visible expression than as a cause.27
Lest one believe that such views were limited to an expla-
nation of sex determination, it is insightful also to examine
Doncaster’s views about cell theory expressed in his 1920
text on cytology. There, Doncaster again upheld the impor-
tance of chromosomes in the life of the cell and organism,
but he backed away from viewing nucleus or the cell as the
primary seats of the phenomena of heredity and develop-
ment. Expressing views that were not dissimilar to those of
Sedgwick and Dobell, Doncaster wrote in a long passage:
The cell theory in its original and crude form regarded an
organism as composed of a horde of discrete units which co-
operate for a common purpose and are modified in various
ways to make that co-operation more effective, much as a
human community consists of many separate individuals,
having different occupations and co-operating for their com-
mon good. According to this idea the individuality of any
organism arose from an integration of the individualities of
its separate cells, and is thus a corporate individuality such
as may exist in a school or a regiment. Nowadays, however,
opinion tends in the opposite direction – to regard the organ-
ism as the individual, with a common life running through it
all, and the cells not as units of which it is built up but rather
as parts into which it is divided in order to provide for the
necessary division of labour involved in so complex a process
as life. The conception of the cell thus remains, but no longer
requires or is capable of the strict definition that was needed
when the word was supposed to represent a fundamental bio-
logical entity. Organisms may be non-cellular if they are not
divided up into cells; portions of organisms may exist which
are not strictly cells in the old sense of the word (for example
Mammalian red blood-corpuscles) and yet have so much the
character of cells that the term may well be applied to them.
The word, in fact, may conveniently remain as a useful de-
scriptive term, implying as a rule a portion of protoplasm
containing a nucleus in immediate physiological connection
with it, but from which either the nucleus or perhaps even
the surrounding protoplasm may sometimes be absent28.
Indeed, rather than regarding the nucleus as ‘the funda-
mental and all-important entity’, Doncaster advised that
‘it is probably better to regard not only cells but also
nuclei as rather parts of an individual whole than to think
of them as units out of which that whole has been built up’.
His holistic views are typical of those who held an epi-
genetic conception of organic development. This epigenetic
tradition within British biology continued to reject the
58 Endeavour Vol. 25(2) 2001
preformationist tenets of German cell theory, reinforced
by Weismannian heredity, in which the cell (and its nuclear
constituents) was regarded as the elementary unit of the
organism and the material basis responsible for organic
vitality. Modern epigeneticists could accept that the chromo-
some and gene were important in the life of the cell and
in heredity, but they mediated their importance by linking
their action to physiological processes occurring in the
cell and organism as a whole.
Conclusion
What conclusions can we draw from this survey of British
cytologists who discussed the connection between Mendel
and meiosis? First, it appears that, Bateson notwithstand-
ing, the conceptual and empirical grounding of cytology
benefited from the Sutton–Boveri hypothesis linking the
chromosomes with mendelian heredity. That mendelism
in Britain failed to profit from this work probably cannot
solely be attributed to Bateson’s influence but also to the
deaths of Lock, Smith and Doncaster during the First
World War or shortly thereafter, and Agar’s emigration to
Australia in 1919 to take up the professorship in zoology at
Melbourne. Second, although leading British cytologists
readily adopted the chromosome theory of heredity, not all
were members of the neo-preformationist camp. Dobell rep-
resented the extreme in questioning of the role of chromo-
somes in mendelian heredity and cell theory itself, whereas
Lock, Gregory,Agar, Smith and Doncaster fully accepted
the chromosome theory29. Agar appears to have held pre-
formationist views, whereas Smith and Doncaster had
epigenetic leanings30. They and other early 20th century
British biologists, influenced by a long epigenetic tradition
in British biology and yet stimulated by the remarkable find-
ings of genetics, attempted to synthesize the evidence for the
material basis of heredity – the new preformationism – with
the tenets of epigenesis. They accepted the association of
mendelizing factors with the chromosomes but assumed that
these morphological entities interacted with the physiologi-
cal processes of the cell and organism. Hence, they di-
minished the preformationist connotations of the chromo-
some theory by linking it to physiological processes in the
cell and developmental aspects of cellular differentiation.
Hence, the acceptance of the chromosome theory of
heredity did not preclude a biologist from holding a physio-
logical view of cells and a holistic view of their importance
in the life of the organism. Such an epigenetic perspective
persisted within British biology well into the 1940s. John
R. Baker, for example, began his classic 1948 history of the
cell theory with the justificatory statement that ‘Several
zoological text-books published during the last two decades
have cast doubts on the validity of the cell-theory.’Criticisms
of cell theory along the same lines as those of Doncaster
were echoed in the writings of James Gray, professor of
zoology at Cambridge, D’Arcy Wentworth Thompson
and Eduard Stuart Russell31. Such biologists could accept
the cell, nucleus and chromosomes as important elements
in the life of an organism and yet avoid extreme morpho-
logical determinism by stressing the role of metabolic and
physiological mediation between the gene, cytoplasm and
the differentiating organism as a whole.
Notes and references
1Sutton, W.S. (1902) Morphology of the chromosome group
in Brachystola magna. Biol. Bull. 4, 24. See also McKusick,
V.A. (1960) Walter S. Sutton and the physical basis of
mendelism. Bull. Hist. Med. 34, 487–497; and
Martins, L.A-C.P. (1999) Did Sutton and Boveri propose the
so-called Sutton–Boveri chromosome hypothesis? Genet.
Mol. Biol. 22, 261–271
2Farmer, J.B. and Moore, J.E.S. (1905) On the maiotic phase
(reduction divisions) in animals and plants. Q. J. Microsc.
Sci. 48, 489–557, p. 492. Fifteen years later, the cytologist
W.E.Agar offered an interesting account of discrepancies
between the descriptions of various observers. ‘The
researcher can only select for study a minute fraction of the
mass of objects presented to him, and inevitably those
objects appear to him significant, and therefore worthy to be
studied, which fit into his preconceived ideas. If a cytologist
sets out to study the gametogenesis of some animal, he will
probably pass under review through his microscope many
hundreds of thousands of cells. Out of these he can
necessarily only select a minute proportion for detailed
study. The cells which he thus selects are, of course, those
which seem to him to represent stages in the process which
he is endeavouring to reconstruct. If he has already formed a
theory regarding this process, having a more definite mental
image of the process as conceived by him than of the
possible alternatives he more readily picks out for study
those objects which appear to favour his theory than the
others, which he rejects (as he is bound to reject the great
majority) as equivocal or of no significance. This certainly
appears to be the explanation of the partisan nature of so
much cytological work.’Agar, W.E. (1920) Cytology, with
Special Reference to the Metazoan Nucleus, p. vii,
Macmillan
3Baxter, A. and Farley, J. (1979) Mendel and meiosis. J. Hist.
Biol. 12, 137–173, p. 139
4For an illustration of this viewpoint, see Bourne, G.C.
(1894) Epigenesis or evolution. Sci. Prog. 1, 105–126
5Olby, R. (1987) William Bateson’s introduction of
mendelism to England: a reassessment. Br. J. Hist. Sci. 20,
399–420; Richmond, M.L. Women in the early history of
genetics: William Bateson’s school of genetics at
Cambridge University, 1900–1910. Isis (in press)
6Coleman, W. (1970) Bateson and chromosomes:
conservative thought in science. Centaurus 15, 228–314;
Olby, R. (1989) Scientists and bureaucrats in the
establishment of the John Innes Horticultural Institution
under William Bateson. Ann. Sci. 46, 497–510,
pp. 507–508; Van Balen, G. (1987) Conceptual tensions
between theory and program: the chromosome theory and
the mendelian research program. Biol. Philos. 2, 435–461,
p. 436
7Richmond, M.L. (2000) T.H. Huxley’s cell theory: an
epigenetic and physiological interpretation of cell structure.
J. Hist. Biol. 33, 247–289
8Sedgwick, A. (1894) On the inadequacy of the cellular
theory of development, and on the early development of
nerves, particularly of the third nerve and of the sympathetic
in Elasmobranchii. Q. J. Microsc. Sci. 37, 87–101
9Dobell, C.C. (1911) The principles of protistology. Arch.
Protistenk. 23, 269–310. See also Corliss, J.O. (1999)
Annotated excerpts from Clifford Dobell’s 88-year-old
insightful classic paper, ‘The principles of protistology’.
Protist 150, 85–98; and Richmond, M.L. (1989) Protozoa as
precursors of Metazoa: German cell theory and its critics at
the turn of the century. J. Hist. Biol. 22, 243–276
10 Dobell, C.C. (1925) The life-history and chromosome cycle
of Aggregata eberthi [Protozoa: Sporozoa: Coccidia].
Parasitology 17, 1–136, p. 122
11 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity and Evolution, pp. 237–238, John
Murray
12 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity and Evolution, pp. 248–250, John
Murray
13 Gregory, R.P. (1905) The abortive development of the pollen
in certain sweet peas (Lathyrus odoratus). Proc. Cambridge
Philos. Soc. 13, 148–157. Gregory, R.P. (1911) Experiments
with Primula sinensis. J. Genet. 1, 73–132
Endeavour Vol. 25(2) 2001 59
14 Agar, W.E. (1911–1912) The spermatogenesis of
Lepidosiren paradoxa. Q. J. Microsc. Sci. 57, 1–44, p. 3
15 Agar, W.E. (1911–1912) The spermatogenesis of
Lepidosiren paradoxa. Q. J. Microsc. Sci. 57, 1–44, p. 28
16 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity and Evolution, pp. 250–253, John
Murray. Lock concluded that ‘the facts of experiment and of
microscopic observation fit in with one another in a
remarkable way, and that the Mendelian theory throws
considerable light on the minute features of cell anatomy’
17 Allen, G.E. (1978) Thomas Hunt Morgan: The Man and His
Science, pp. 159–163, Princeton University Press
18 Farmer, J.B. and Moore, J.E.S. (1905) On the maiotic phase
(reduction divisions) in animals and plants. Q. J. Microsc.
Sci. 48, 489–557, p. 496
19 Smith, G.W. (1906) Rhizocephala. In Fauna und Flora des
Golfes von Neapel und der Angrenzenden Meeres-
Abschnitte (Vol. 29), pp. 82, 89, R. Friedländer & Sohn
20 Smith, G.W. (1909–1910) Studies in the experimental
analysis of sex. 1. On mendelian theories of sex. Q. J.
Microsc. Sci. 54, 577–590; Smith, G.W. (1909–1910) Studies
in the experimental analysis of sex. 2. On the correlation
between primary and secondary sexual characters. Q. J.
Microsc. Sci. 54, 590–604. On p. 590. This ‘sexual formative
substance’, it should be stated, should not be confused with
‘hormones’, a newly proposed theory that he rejected
21 Smith, G.W. (1906) Rhizocephala. In Fauna und Flora des
Golfes von Neapel und der Angrenzenden Meeres-
Abschnitte (Vol. 29), p. 86, R. Friedländer & Sohn
22 All ten parts of Smith’s study appeared in the Quarterly
Journal of Microscopical Science between 1909 and 1914
23 Bateson, for example, provided a critique of Doncaster’s
first published paper. See Doncaster, L. (1904) Experiments
in hybridization, with special reference to the effect of
conditions on dominance. Philos. Trans. R. Soc. London
Ser. B196, 119–173, p. 120. In 1903, Bateson tried to
persuade Doncaster to become his collaborator: Olby, R.
(1989) Scientists and bureaucrats in the establishment of the
John Innes Horticultural Institution under William Bateson.
Ann. Sci. 46, 497–510, p. 507
24 In his review of significant contributions of the previous 50
years to the Quarterly Journal of Microscopical Science,
Gilbert Bourne drew attention to Doncaster’s papers, stating
that ‘the methods are cytological, but the aim is the
elucidation of certain problems in gametogenesis.’See
Bourne, G.C. (1919–1920) Fifty years of the ‘Quarterly
Journal of Microscopical Science’ under the editorship of
Sir E. Ray Lankester, K.C.B., M.A., D.Sc., LL.D., F.R.S.
Q. J. Microsc. Sci. 64, 1–17, p. 15
25 Doncaster, L. (1907) Gametogenesis and fertilisation in
Nematus ribesii. Q. J. Microsc. Sci. 51, 101–113, p. 109
26 Doncaster, L. (1913) On an inherited tendency to produce
purely female families in Abraxas grossulariata, and its
relation to an abnormal chromosome number. J. Genet. 3,
1–10, p. 9
27 Doncaster, L. (1913–1914) Chromosomes, heredity and sex:
a review of the present state of the evidence with regard to
the material basis of hereditary transmission and sex-
determination. Q. J. Microsc. Sci. 59, 487–521, p. 516
28 Doncaster, L. (1920) An Introduction to the Study of
Cytology, p. 4, Cambridge University Press
29 Both Agar and Doncaster attempted to convert Bateson to
the chromosome hypothesis. Doncaster told Bateson that
he could not ‘help feeling that the cytological results of
recent years are so closely in accord with what one must
assume in Mendelian segregation that the two things must
be closely connected.’And even Bateson attempted to
dissuade Dobell from absolute rejection of the chromosome
hypothesis. See Coleman, W. (1970) Bateson and
chromosomes: conservative thought in science. Centaurus
15, 228–314, p. 309, n. 72; and Olby, R. (1989) Scientists
and bureaucrats in the establishment of the John Innes
Horticultural Institution under William Bateson. Ann. Sci.
46, 497–510, p. 508
30 In his 1920 textbook on cytology, for example, Agar
restricted his focus to ‘the nucleus and its constituent parts’,
scarcely touching upon ‘the organization and physiology of
the cell as a whole’. However, such statements as the ‘all-
importance of the nucleus and the essential passivity of the
cytoplasm in the transmission of hereditary qualities’
suggest that Agar held preformationist views. See Agar,
W.E. (1920) Cytology, with Special Reference to the
Metazoan Nucleus, pp. v, 154, Macmillan
31 Baker, J.R. (1948; reprinted 1988) The Cell-Theory: A
Restatement, History, and Critique (Pt 1), p. 103, Garland
Publishing. See also Gray, J. (1931) Experimental Cytology,
p. 2, Cambridge University Press; Thompson, D’A.W.
(1942) On Growth and Form, pp. 341–345, Cambridge
University Press; and Russell, E.S. (1930) The physiological
interpretation of the cell-theory. In The Interpretation of
Development and Heredity: A Study in Biological Method,
Chapter 11, Clarendon Press
32 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity, and Evolution, p. 242, John Murray
33 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity, and Evolution, p. 244, John Murray
34 Lock, R.H. (1906) Recent Progress in the Study of
Variation, Heredity, and Evolution, p. 249, John Murray
60 Endeavour Vol. 25(2) 2001
