THE MYCETOZOA 



151 



while other " spores," called spore-like cells} which fill up the 

 central cavity of the stalk of the fruit-body and make it soUd 

 (Fig. 83, B), are never dispersed and take no part in reproduction. 

 Although the spore-Hke cells do not themselves reproduce the 



Fig. 83. — Sporangia of Arcyria pomiformis. To show the spore-like cells which fill 

 up and strengthen the stalk, but are never set free and take no direct part in 

 reproduction. A, two fruit-bodies on a piece of wood : a, mature but unopened ; 

 h, the sporangium has dehisced and the capilhtium is exposed to view. B, a 

 vertical section through the cup and stalk of a sporangium which has dehisced : 

 a, the membranous stalk-wall ; b, the spore-like cells cohering into a mass of 

 cells which completely fills the stalk ; c, larger, more irregular spore-like cells 

 near the hypothallus ; d, smaller spore-like cells at the top of the stalk, above 

 which in the cup are the true spores e lying free within the network of the 

 capillitium /. C, a group of spore-like cells of medium size, in transverse section, 

 to show their hexagonal form, their walls, and the air-spacea between them 

 (cell-contents omitted). D, two spore-like cells, one very large, the other small ; 

 the cell-contents of the large one are contracted. E, a group of spores. F, a 

 piece of the capillitium. Drawn from niaterial and a preparation supplied by 

 Miss Gulielma Lister. Magnification : A, about 20 ; B, about 84 ; C-F, 

 about 333. 



species, nevertheless they are of advantage to the species in that 

 they strengthen the apparatus in which the ordinary spores are 

 developed. If we are to regard the spore-like cells as morphologic- 

 ally equivalent to the ordinary spores, we must admit that, in the 

 Mycetozoa under discussion, we have another instance of social 



^ For species containing these spore-like cells vide Miss Lister's Monograph. 

 Miss Lister kindly supplied me with material and a preparation from which my 

 Fig. 83 was drawn. 



