90 



NATURE 



[April 15, 1920 



English Cytology, 



An Introduction to the Study of Cytology. By 

 Prof. L. Doncaster, Pp. xiv + 280 + xxiv plates. 

 (Cambridge: At the University Press, 1920.) 

 Price 215. net. 



THE publication of this volume is to be 

 regarded as an event in the progress of 

 cytology. Prof. Doncaster 's new book is not 

 intended to serve as a text-book on cytology, 

 though it contains a wealth of facts; but its aim 

 is to interest the senior student in the subject by 

 pointing out the way in which cytology is related 

 to the great fundamental problems at the root of 

 all biological research. Quite recently Paul 

 Buchner, of Munich, published a new " Hand- 

 buch " of cytology, and it is with pride that we 

 compare the work before us with its German 

 prototype. A great deal of the material in Prof. 

 Doncaster 's book is new, and the work is as 

 strictly up-to-date as is possible when one is deal- 

 ing with a vast and changing subject such as 

 cytology. 



The author's conception of the cell is very 

 broad ; he recognises the important part played 

 by the nucleus, but pays due attention to the Golgi 

 apparatus and mitochondria, which he considers 

 may be of special importance in the life of the 

 cell; useful discussions on the structure of proto- 

 plasm, such as are illustrated by Hardy's work, 

 and on Hertwig's conceptions of the "karyo- 

 plasmatic ratio," are added to this part of the 

 book. The question of the origin and relationships 

 of the centrosome has been treated in a masterly 

 way, and the author shows how J. W. Jenkinson's 

 work on the fertilisation of the Axolotl can pro- 

 vide a middle way between the divergent views — 

 that centrosomes arise from pre-existing centro- 

 somes, and that they may be formed de novo in 

 the cytoplasm. 



Prof. Doncaster steers a careful course through 

 the troubled waters surrounding the various ques- 

 tions with regard to astral rays, spindle fibres, and 

 "mitokinetism." He gives a fair and lucid expose 

 of the various ingenious hypotheses brought for- 

 ward to explain mitotic division, but concludes that, 

 at present at least, no really satisfactory explana- 

 tion of the phenomenon of mitosis has been given. 



Students of cytology are often turned away from 

 entering into the various problems associated with 

 the behaviour of the chromosomes in the germ- 

 cell cycle by the fact that the whole question is 

 obscured by a multitude of ill-digested descrip- 

 tions, theories, and hypotheses. Prof. Doncaster 

 has written an exceptionally clear and able 

 NO. 2633, VOL. 105] 



account of the typical behaviour of the chromo- 

 somes. Never polemical, he gives a straight- 

 forward account which includes on a broad basis 

 all the most modern work on the chromosomes. 

 His first description of maturation is written with 

 an eye to his later accounts of the chromosomes in 

 sex and Mendelism, but he is careful not to con- 

 fuse his preliminary survey by bringing in 

 debatable matter. Here the student will find a 

 conveniently introduced resume of the Chias- 

 matypy hypothesis of Janssens, which has gained 

 such prominence among Mendelians. 



The modern work on the behaviour of the cyto- 

 plasmic inclusions during spermatogenesis has 

 been the subject of careful descriptions. Prof. 

 Doncaster has treated the matter in an able 

 manner, and the worker unacquainted with the 

 Golgi apparatus and mitochondria will find in this 

 book a readable and accurate account of the 

 present state of our knowledge. The various 

 questions surrounding the formation of egg yolk 

 are not treated at length, and should be included 

 in a future edition ; we refer especially to the 

 work of Weigl, Hirschler, Rio Hortega, etc. 

 The author exhibits a commendable scepticism 

 with regard to the specificity of the so-called 

 "chromatin " dyes, and points out in several parts 

 of the book that cytoplasmic bodies unrelated ta 

 chromatin may stain basophil, and yet not be true 

 chromatin. 



In his chapter on segmentation Prof. Doncaster 

 succeeds in bringing out the fact that we have 

 really proceeded a very short distance in the 

 elucidation of the great problems surrounding even 

 the first stages of animal development. In a later 

 part of the book the author discusses some of 

 these problems. 



The subject of parthenogenesis is treated at 

 length, and the author draws freely from his own 

 researches on this fascinating subject. He recog- 

 nises four main sections with regard to the 

 behaviour of the chromosomes in naturally parthe- 

 nogenetic animals. We are sorry to see that he 

 has not adopted Sir Ray Lankester's suggestions 

 as to the nomenclature of parthenogenesis. In 

 his treatment of the subject of artificial partheno- 

 genesis Prof. Doncaster points out that there are 

 numbers of problems which are still unsolved with 

 reference especially to the determination of sex. 

 The question of the restitution of a diploid chromo- 

 some number in some artificially parthenogenetic 

 animals is also peculiar, and its mechanism ill- 

 understood. A special chapter on the chromo- 

 somes in sex-determination has been added, 

 somewhat on the lines of the author's "Deter- 



