some essential stages were not present in the photographic material at the 

 author's disposal. If so, he would have done well to solicit the co-operation 

 of others. In any case the title of the work is misleading, and oddly enough 

 the author more or less concedes this in his preface by saying that it only 

 deals with certain aspects of the topic. 



The atlas depicts the ultrastructure of the gametes of five laboratory animals 

 before, during, and after fertilization: rabbit, golden hamster, ferret, mouse, 

 and gerbil (of the latter two species only a few illustrations are included). 

 The accompanying text is kept brief. Chapter V deals with ferritin injection 

 experiments aimed at assessing the possibility of exchange of material between 

 the oocyte and the perivitelline space. 



Most of the plates are full-page size, and most are accompanied by line 

 drawings showing the approximate orientation of the sections depicted. These 

 are not always entirely satisfactory, and sometimes puzzling. Part of the plates 

 are of less than superior quality. Judging from the fixation procedures used 

 these may date from a time when methods were not yet optimal. 



The book is exceedingly well produced at a reasonable price. The biblio- 

 graphy covers more than five pages. Unfortunately the book has no indexes. 



23 ORGANIZATION AND DEVELOPMENT 



OF THE EMBRYO 



1969 



by R. G. Harrison f Yale Univ. Press 



Edited by S. Wilens London 



314 pp., 151 figs.. 7 pis., 3 tbs. SBN 300 01 155 5 



Price: 135 s. 



Contents: Foreword; Preface; Synopsis of the Silliman Lectures; Ch. 1 Cellular differen- 

 tiation and internal environment; Ch. 2 Harrison stages and description of the normal devel- 

 opment of the spotted salamander, Amblystoma punctatum; Ch. 3 On the status and significance 

 of tissue culture; Ch. 4 On the origin and development of the nervous system studied by 

 the methods of experimental embryology; Ch. 5 Relations of symmetry in the developing 

 embryo; Ch. 6 Heteroplastic grafting in embryology; Ch. 7 Recapitulation and conclusion; 

 Supplementary references cited in notes from the Silliman Lectures; Ross G. Harrison's 

 Publications 1893 — 1948; Memorial tributes; Index 



In 1949 Prof. R. G. Harrison delivered the Silliman Lectures at Yale 

 University, but he was prevented from preparing them for publication by 

 illness. This book does not contain the actual text of the lectures, but reprints 

 of five of his papers dating from 1927 to 1945, which he used as the major 

 source for the lectures. Dr. Wilens, his life-long associate, has re-edited these 

 by inserting illustrations and excerpts from his Silliman Lecture notes that 

 bridge the interval between the publication date of the papers and the delivery 

 of the lectures. She has moreover added a chapter consisting of the original 

 figures of his famous series of normal stages of Amblystoma punctatum with 

 the descriptions belonging to them, which had never been available in published 

 form. As a final chapter she has added Harrison's own "Recapitulation and 

 conclusion" from his Silliman Lecture notes. 



Dr. Wilens has also written a ten-page preface characterizing Harrison as 

 a scientist and teacher, and has compiled a complete bibliography of his 

 publications. 



The book has been produced with the utmost care and constitutes a worthy 

 tribute to the great man that Harrison was. 



22 



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