288 The American Naturalist. [April, 



forming a single encysted spore (fig. 13, h). 



Why this mechanical adhesion of the swarm spores into a 

 Plasmodium? It would seem a scheme adopted by the plant 

 to better protect the enevsted spores. 



2. IntheM!/xr»»!,c«<,s V ro\*r(thi- higher Slime Molds), the 

 mode of life is practically the same as in the Acrasiese,hut here, 

 when the swarm spores fuse to form the plasmodium ; the fusion 

 is complete so far as the protoplasm- are concerned, but still 

 there is a lack of a thorough fusion of all the elements as the 

 nuclei remain apparently ununited (fig. 14). 



In some Mi/.comiiatts we find an indefinite number of swarm 

 spores uniting to form the plasmodium, but in others the 

 number thus fusing is reduced to a very few. Thus coupled 

 with the growing complexity of the fusion or /)sC(i(h<-co)iju</a- 



ber of elements fusing. 



3. Between this process and that described as conjugation 

 there are many interesting intermediate forms. Sometimes 

 three or four spores of low Al^e unite as if to gather sufficient 



strength to make a 



combined start in life. In DictyosipH 



hippuroides Areselu 



■ ug 1 has observed and figured the union < 



three zoospores. ] 



hi Acdahiil <rrift mediterranea DeBary an 



Strasburger have 



tiuur.il the copulation of several swan 



spores (figs. 15 and 



16). This multiple conjugation has ah 



4. In Ulothris we find the d 

 ther. Here the protoplasm of c 

 divides up into numerous little j 



^reschoug, Nova Acta., Reg. Soc. Ser. ] 

 "DeBary and Strasburger Bot. Zeit., Bd. : 



