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THE AMERICAN BOTANIST 



The present vogue of eugenics renders timely a little book 

 on "The Evolution of Sex in Plants," by Dr. J. M. Coulter, 

 head of the department of botany in the University of Chicago. 

 Mo'St of the matter in the book is not new in the sense of never 

 having been pubHshed before, but its arrangement gives a new 

 significance tO' old facts and makes the subject clear even to the 

 general reader. The author points out the fact that sex in 

 plants is not essential to reproduction. Taking the whole plant 

 world into consideration he finds that the multiplication of indi- 

 viduals proceeds more extensively by asexual than by sexual 

 means. Sexual reproduction, in fact, is the latest of the 

 methods of reproduction to be developed and seems rarely to 

 occur except as vegetative vigor weakens. Its occurrence, how- 

 ever, renders organic evolvition more rapid and more varied, 

 since by this method new individuals are produced with the 

 characters of two different lines of ancestry mingled. Among 

 the subjects discussed in explaining the origin of sex are 

 asexual reproduction, the evolution of sex organs, the alter- 

 nation of generations and parthenogenesis. Dr. Coulter is a 

 clear and forceful writer and his book is sure to be of much 

 help in introducing the beginner to this little-understood phase 

 of botany. The volume contains 137 pages and 46 illustrations 

 and is pubfished by the University of Chicago Press at $1.00 

 net. 



