GAMETOGENESIS IN PLANTS^ 



The evolutionary origin of the reproductive cells fur- 

 nishes one of the most fundamental problems connected 

 with genetics, for upon a clear understanding of the sub- 

 ject depends the satisfactory solution of many subsidiary 

 problems relating to animal and plant breeding. The 

 value of hybridization and inbreeding; the meaning of the 

 pure line hypothesis; the principle of cumulability, etc., 

 may here be mentioned. Therefore, whether or not one 

 agrees with the conclusions presented, studies from widely 

 divergent standpoints which bear upon the question are 

 to be welcomed. It is only through an analysis of the 

 opinions thus advanced that there will develop a perspec- 

 tive which will eventually permit the solution of the 

 problem. 



It is in this connection that the conclusions of Professor 

 Coulter as set forth in "The Evolution of Sex in Plants"^ 

 are of interest, representing as they do the views of one 

 whose attainments in biology have by no means been con- 

 fined to the field of plant morphology. Presented in a 

 clear and interesting manner so far as the facts are con- 

 cerned, the volume furnishes a valuable resume of the 

 subject from the botanical standpoint. It is evident, 

 however, that a certain narrowness must exist in such a 

 presentation, for a problem of this nature demands that 

 plant biology and animal biology supplement one another 

 from the experimental as well as from the morphological 

 and cytological side. Gametogenesis had its beginning 

 not, as Coulter suggests, among organisms far above the 

 most primitive plants, but among unicellular flagellate 

 forms whose representatives partake of the nature of 

 both plants and animals and from which have arisen the 

 various groups of plants in general. Sexuality, once hav- 



■"^By John Merle Coulter, head of the department of botany, Univ. of Chicago. 

 Univ. of Chicago Press, December, 1914. 



♦Reprinted from The American Naturalist, vol. 50 (1916), pp. 498-501. 



