35 2 BOTANICAL GAZETTE [october 



the reduction division determines the sexual condition, and the 

 peculiarity of this division, as compared with ordinary division, is 



gametes 



pared with other nuclei. If gametes 



this 



division. 



In well balanced alternation of generations, as in bryophytes 



many 



gametes 



mitted through the cell generations of the gametophyte is a subject 

 of speculation, but certainly something maintains a continuity 



gametes 



hiefly 



seed plants, the cell generations between spore and gamete become 

 fewer and fewer, until finally sperms are reached in two successive 

 cell divisions, and the eggs are reached in one to three successive 



divisions. 



elimination 



entirely and the occurrence of reduction in connection with gamete- 

 formation, as in animals. 



In conclusion, the impression one obtains of sexuality as a 



method of reDroduction is that it renresents nrotonlasts engaged in 



difficulties 



e multiplication, and that its 

 makes organic evolution more 



more 



University of Chicago 



