THE MYCETOZOA 133 



dry they remain alive for over three years. Many species 

 pass their period of growth, i.e. their plasmodial stage, 

 among decaying leaves, others grow hidden within rotten 

 wood, emerging only to form sporangia. Shady spots where 

 leaves are left in heaps suit such species as live among dead 

 leaves : the stages of one of these are shown in Fig. 36, and 

 in the Frontispiece a place in which it throve. The zoospores 

 swim and creep alternately ; owing to frequent binary 

 division they are often seen in pairs joined base to base, 

 struggling to be free from each other. With patience even 

 in simple slide-and-cover cultures the fusion of two zoospores 

 that have withdrawn their flagella may be seen ; thus is 

 formed the zygote or plasmodium at its inception. 



On cultivating spores in water we notice how variable 

 is the hatching process both in the same and in diiferent 

 species ; the spores of Reticularia Lycoperdon usually have 

 the spore-capsule thinned at one side, and they often hatch 

 in an hour. 



Most species require 12 hours, some much longer. When 

 hatching has occurred we note that the characters of zoo- 

 spores of different species vary : in the winter species, 

 Trichia varia, for example, the zoospores move in a leisured 

 way, and the nucleus is hard to detect ; those of Didymium 

 and other genera move briskty and their nucleus and 

 nucleolus are plain to see. 



Stages of sporange-formation. As seen in a species of 

 Stemonitis stages of sporange-formation are shown in 



