165 



Notwithstanding the special form of approach, this book can still be recom- 

 mended as an interesting guide into the wide field of regeneration and 

 morphogenesis in general. 



P. D. NIEUWKOOP 



..EMBRYOLOGY" 

 1949 



by L. G. Barth The Dryden Press 



330 pp. with 194 figs New York 



price: $ 5.50 



The author emphasizes the role of developmental processes in the entire hfe 

 of the animal, so that a general knowledge of these processes is important 

 for the premedical student, the college student or the biological student. 



The various chapters have been mainly arranged chronologically; the first 

 ones are therefore deahng with the oviposition. the structure of the unfertilized 

 egg, the process of fertihzation, cleavage, gastrulation and neurulation after 

 which the later development has been treated according to organ systems. 

 Special chapters have been inserted on the problem of field action, inter- 

 relationships of developing structures, regeneration, growth and its relation 

 to hormones, and the problem of sex differentiation, while some special chap- 

 ters have been devoted to the development of the frog egg, the development 

 of the chick embryo and to mammalian development. 



Each chapter has been treated very clearly and conveniently, and has been 

 illustrated by simple but very instructive diagrams. The principle results of 

 descriptive and experimental analysis and the existing theories have been 

 properly discussed in each chapter. 



The text has been very clearly written and is very concise and accurate, 

 so that it is a pleasure to read this textbook, which has moreover been 

 illustrated with very well reproduced photographs. It is a pity that some of 

 the pictures of the development of the chick blastoderm and the mammaHan 

 embryo are too strongly reduced in size so that they are not so easily 

 surveyable as the majority of the figures, while also some of the diagrams 

 are somewhat too strongly schematized, which might interfere with a re- 

 cognition of the natural relationships and topography. The chapter of sug- 

 gested readings gives an extensive list of other textbooks to be referred to 

 on each subject. 



We will highly recommend this textbook for teaching purposes and as a 

 source for an introduction into the field of embryology for the embryology 

 student. 



P. D. NIEUWKOOP 



.,MORPHOGENESIS, AN ESSAY ON DEVELOPMENT" 



1952 



by J. T. Bonner Princeton University Press 



296 pp. with 90 figs and 9 plates Princeton, N.J. 



price: $ 5. — 



The complexity of the living organism and the enormous variety in forms 

 induces us to search after the main principles on which the organisation of 



