BOOK REVIEWS 245 



education as follows : 'The field of sex education is new — so new 

 that we must begin at the top — begin by 'educating the educators.* 

 Small wonder that teacher, parent and physician hardly know 

 where to begin or how far to go. Mistakes are bound to be made 

 on the way — the reformer is always radical, thank heaven ! and 

 always swings a little too far. The time will come when sex 

 hygiene will be a natural and inevitable part of education, and 

 those whom we fain would instruct will no longer blush — still less 

 will they giggle. Meanwhile, let us bear up under the giggling of 

 the present generation in the security of the belief that braving 

 the giggles of today may help to check the tears of tomorrow." 



The Evolution of the Vertebrates and Their Kin. By Wil- 

 liam Patten, Ph. D. P. Blakeston's Sons & Co.. Philadelphia. 

 Pp. xxi -)- 486 ; 309 illustrations. $4.50. 



Any one who has attended the yearly meetings of the Amer- 

 ican Association for the Advancement of Science has repeatedly 

 heard papers by Dr. Patten and his students and has seen models 

 of the animals which he considers the ancestors of the vertebrates, 

 but there was no book in which one could find a statement of his 

 interesting views until the appearance of this admirable volume. 

 The book is not intended for the amateur but only for one who is 

 willing to wade deeply in the conflicting currents of opinion re- 

 garding the interpretation of embryological and morphological 

 facts. Dr. Patten presents his evidence of the rise of the ver- 

 tebrate from an arachnid ancestry in a masterly way and explains 

 so many of the peculiarities of vertebrate anatomy thereby that 

 it is difficult to get away from his conclusions. It is a book that 

 every student of evolution will welcome as a valuable contribution 

 to the discussion of possible lines of ascent. 



Ah, The Cave Man. By William Lewis Nida. A. Flanagan 

 Company. Chicago, 166 pp. 50c. 



In the preface to this little book the author says: 



"For nearly a dozen years it has been my pleasure to ob- 

 serve the intense interest shown by second grade pupils as they 

 listen to the 'Story of Ab' from the lips of their teachers. No 

 other book available has held our children so completely in its 

 spell. 



"By special arrangements with Messrs. Doubleday. Page & 

 Co.. and Mr. ^^'aterloo. the author of 'Ab'. the work is now readv 

 for the little folks." 



On the theory of recapitulation it is supposed that the average 



