270 



PLANT STUDIES 



While the ordinary method of reproduction tlirough tlie 

 growing season is l)y means ot these rapidly germinating 

 spores, in certain conditions a sexual process is observed, 

 by whicli a heavy-walled sexual spore is formed as a resting 

 sjwre, able to outlive unfavorable conditions. ]'>ranches 

 arise from the hypha? of the mycelium just as in the forma- 







FiG.'^:^0. ]\r;ilure spoiim^ium nr ,1A/r^v, sln'wini: Fii;. 2.37. Unrsted sporangium of 



tin; Willi (.1), llu' iiiinu'T'fjti.s spore,.; (r). jind M'icitr, the ruptured wall not 



the enliniiellii I /;)--tliiit is. the partition wall lieini; shown. mihI the loose 



imshed lip into the eavity of the siMiraiigium. spores lelherin;,' to tile enill- 



— JI IB. mella.-:\looKK. 



tion of sporophores (F'ig. 2ImS). Twd contiguous branches 

 come in conta,ct by their ti])s (Kig. "-'•i''^, .1), the tips are cut 

 off from the mtiin ctenocytic body by ptirtition walls (Fig. 

 S^i.S, />'), the Willis ill conttict disorganize, the contents (if 

 tlio two ti]) cells fuse, and a hetivy-walled sexmil spore is 

 the result (Kig. "•;!S, ('). It is evident that the process is 

 conjugation, suggesting the t'oujugiitc forms a.mong the 



