opmental genetics, and more specifically in the field of sex differentiation, it 

 is very useful to have the most important information on sex chromosomes 

 brought together in a comprehensive volume. 



The book gives a step-by-step reconstruction of the phylogenesis of the 

 sex chromosomes in relation to the evolution of vertebrate genomes, and uses 

 this analysis to broaden our understanding of the nature of sex-determining 

 factors, sex-linked genes, and the dosage compensation mechanism. Wherever 

 knowledge on vertebrates is scanty or lacking, Drosophila is used as an 

 example to elucidate certain principles. 



The book is organized in three parts. Part I (5 chapters) discusses the 

 evolution of vertebrate sex chromosomes and genomes. Part II (7 chapters) 

 deals with the evolution of the dosage compensation mechanism for sex-linked 

 genes. Part III finally treats the so-called sex-determining factors and the 

 act of sex determination. It consists of a chapter elucidating what little is 

 known about the so-called sex-determining factors (5 pp.), and a chapter 

 discussing the time and place of action of sex-determining factors in ontogeny 

 (20 pp.)- The latter chapter has sections on primordial germ cells, on the 

 origin and differentiation of the gonad and the hormonal factors involved, 

 and on the role of the pituitary in sex differentiation. 



The book is well-produced and well-illustrated. It is concluded by author 

 and subject indexes. 



6 MARSHALL'S PHYSIOLOGY OF REPRODUCTION 



3rd ed., 1966 

 Vol. Ill 

 Editor: A. S. Parkes Longmans, Green and Co. Ltd. 



11 84 pp., 365 figs., 68 tbs. London 



Price: $ 70.— 



Contributors: Allanson (London), Deanesly (Cambridge), Donovan (London), Harris 

 (Oxford), Kellie (London), Morris (London), Parkes (Cambridge), Rowlands (London) 



The final volume of the third edition of this standard work, which was 

 originally scheduled for 1961, has now appeared, 14 years after Vol. II. which 

 was the first volume of the third edition to appear. Notwithstanding this time 

 lag, continuity was guaranteed by the fact that both the second (1922) and 

 the third edition appeared under the eminent editorship of A. S. Parkes. 



It is not our intention to review Vol. Ill extensively. The following remarks 

 may suffice. The volume deals almost exclusively with the endocrinology of 

 reproduction in mammals, a subject which had to be split off from Vol. I, 

 part 2, during the preparation of the third edition, and has now grown into 

 the largest of the four volumes. The chapter of most immediate interest to 

 embryologists is that by Ruth Deanesly, entitled "The endocrinology of 

 pregnancy and foetal life" (134 pp. and a bibliography of 39 pp.). It has 

 sections on pre-implantation stages, delayed implantation, the endocrine 

 function of the placenta, foetal reproductive and endocrine organs, sex dif- 

 ferentiation, etc. 



7 MODERN GENETICS 



Vol. 2, 1966 

 by J. A. Serra Academic Press 



628 pp., 82 figs., 2 pis., 43 tbs. London - New York 



Price: 135 s. 



Vol. 1 of this excellent comprehensive textbook for advanced students was 

 announced in the 11th main issue of this periodical, 1965, p. 338. The book 

 may be used with profit as a work of reference. Parts of it may be read in- 



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