THE MYCETOZOA 137 



as the sporanges dried, becoming separable, brittle, and easy 

 to detach from their stalks. 



The manner in which the stalks are formed and prolonged 

 into the columella as seen under low magnification is shown 

 in Fig. 38, 7 to 10. 



A small plasmodium may become a single sporange. 

 Sporange-formation as seen in Trichia, Arcyria, and other 

 genera with clustered fruits begins in the same way as in 

 Stemonitis. In some genera such as Eeticularia, and Fuligo 

 the sporangia fuse into a mass called an aethalium. 



The most familiar example of an aethalium is perhaps 

 that of Lycogala epidendrum, whose plasmodium emerges 

 from rotten wood as coral beads and whose fused sporanges 

 make rounded bodies like small puff-balls, Fig. 43, 15, and 

 change from rose-colour, through grey to brownish. The 

 collection of grey-pink spores within the tough membrane 

 of the ripe aethalia farther reminds one of puff-balls and 

 explains how the whole class of Mycetozoa were at one time 

 called Myxogastres, and were thought to belong to the 

 same group of fungi as the Gasteromycetes. 



In Ceratiomyxa fruticulosa, Fig. 45, the single species 

 which constitutes the exosporous subdivision of the Myce- 

 tozoa, the sporangia are not closed ; the spores being 

 formed at the end of short stalks on finger-like sporo- 

 phores. 



The life-history of Mycetozoa is still imperfectly known : 

 I have found spores unchanged in the gut of earthworms ; 



