NYCTALIS ASTEROPHORA 455 



spores may thus come into existence. A cell about to produce a 

 chlamydospore becomes swollen in the middle, the cell-contents 

 then collect in the swelling, and a cross-wall is formed at each end 

 of the swelling. Thus the cell becomes divided into three cells, a 

 large central chlamydospore in course of development and two small 

 empty end-cells. The contents of the chlamydospore now contract 

 somewhat and become surrounded by a new wall. Next the wall 

 bulges forward in certain places and thus the chlamydospore comes 

 to take on its star-like shape. The wall now thickens and turns 

 brown. Finally, owing to the swelling of the walls of the empty 

 end-cells between adjacent chlamydospores, the individual chlamydo- 

 spores become free. This mode of formation of the chlamydospores 

 of Nyctalis asterojphora is essentially similar to that of the chlamydo- 

 spores of Ptychogaster and Fistulina. The germination of the 

 chlamydospores takes place with difficulty, for it occurs only on the 

 surface of a Russula fruit-body. The production of the chlamydo- 

 spores is extremely rich and long-continued and, frequently, whole 

 mycelia become converted into them. 



Only seldom in a mycelium under cultivation do certain parts 

 grow more vigorously. In these parts the fruit-bodies of the 

 Nyctalis arise by the growth of hyphae which form a knot and then 

 develop in the same manner as the fruit-bodies of other Agaricineae 

 having a rudimentary volva. The snow-white pileus begins to turn 

 brown when the stipe elongates. Then its hyphae form chlamydo- 

 spores in the same manner as the mycelium, except for the fact 

 that chlamydospore-formation is restricted to the upper part of the 

 pileus where the chlamydospores become heaped up in thick layers 

 as a brown powder. Most of the nutrient substance at the dis- 

 posal of the fungus becomes used up during this fructification, and 

 when chlamydospore-formation begins, growth in size comes to an 

 end. The hymenium, as a rule, becomes aborted, and only in large 

 fruit-bodies in which chlamydospores are formed late do the basidia 

 produce basidiospores. Thus in Nyctalis asterophora, as regards 

 chlamydospores and basidiospores, we have similar conditions to 

 those which prevail in Ptychogaster alhus} 



Brefeld's investigation of Nyctalis asterophora, so admirably 

 ^ For an account of Ptychogaster alhus, vide infra, vol. iv. 



