X. Use of the oocyte protein-synthetic system for the analysis of the RNA 

 matrix (Borovkov, Sviridov, Kuzin, Korochkin) . 



Extensive chapter bibliographies (Russian and other) ; good line drawings, 

 diagrams and photographic plates. 



39. 



A.GLUCKSMANN. 1978. SEX DETERMINATION AND SEXUAL DIMORPHISM IN MAMMALS 

 Wykeham, London. The Wykehara Science Series. 179 pp., 10 figs., 8 tabs., 

 subject index. £ 4.75 (paper) 



Contents (abridged): I. Sex determination, II. Sexual dimorphism in adult 

 mammals. III. Common features in the sex determination and sexual dimor- 

 phism of mammals 



This book was written for beginning students, but due to its rather dull 

 style and very sparse illustrations it is doubtful whether it will capti- 

 vate the average student. It is interesting enough for the dedicated reader 

 and contains no factual errors. 



We only consider part I here, which occupies less than half of the text. 

 Here the main objection is that the major sex-determining genes, Tfm and 

 H-Y, are mentioned cursorily but are not placed in proper perspective. This 

 is a missed chance. 



The illustrations are restricted to a few diagrams. 



40. 



P.D.NIEUWKOOP and L. A. SUTASURYA. 1979. PRIMORDIAL GERM CELLS IN THE CHOR- 



DATES; embryogenesis and phylogenesis 



Cambridge Univ. Press, Cambridge, etc. Developmental and Cell Biol. Series 



7. XII, 187 pp., 45 figs., 2 tabs., author, taxonomic and subject indexes. 



£ 14.50 



Contents: 1. General introduction, 2. Early embryogenesis, with special 

 reference to mesoderm formation, 3. Characteristics of the primordial 

 germ cells, 4. The extra-gonadal and one-time origin of the primordial 

 germ cells, 5. Site and mode of origin of the primordial germ cells, 6. 

 The formation of the gonadal anlagen, 7. The migration of the primordial 

 germ cells, 8. Phylogenetic significance of the embryological data pre- 

 sented, 9. Concluding remarks and some perspectives for further analysis 



The writing of this scholarly monograph was prompted by the discovery by 

 the senior author and his collaborators of mesoderm induction in the amphib- 

 ian blastula, and the later discovery by the two present authors of the me- 

 sodermal origin of the primordial germ cells in the urodelan amphibians, a 

 situation that contrasts markedly with that encountered in the anurans. The 

 authors have now assembled all the available information on the descriptive 

 and experimental embryology of the primordial germ cells and early gonad 

 formation in the chordates. In the course of the book they arrive at some 

 interesting broad generalisations, but they are careful to point out to 

 what extent these are speculative and where the gaps in the evidence are 

 that must be filled. 



The table of contents above largely speaks for itself. Ch.2 forms the em- 

 bryological basis for the rest of the book. The generalisation here is that 

 probably in all chordates the mesoderm arises epigenetically from the ecto- 

 derm under the influence of the endoderm. Ch.5 is another pivot in the book, 

 since it ends in the conclusion that the two modes of primordial germ cell 

 formation encountered among the amphibians, i.e. preformation in the endo- 

 derm VS. epigenetic origin from the mesoderm, can probably also be found in 

 other chordate groups. This and other evidence then leads in ch.8 to the 

 tentative hypothesis of an early bifurcation in vertebrate evolution leading 



218 



