CARP0PH7TA. 203 



upon the vegetative filaments before the formation of the 

 spore-fruit, but there are grave doubts as to the correctness 

 of the observations, and it is the general opinion that these 

 organs have become obsolete. 



372. The vegetative filaments (mycelium) of some 

 species of this order (as Fomes fomentarius, etc.) often 

 form thick, tough, whitish masses of considerable extent in 

 trees and logs, and constitute the Amadou, or German tin- 

 der of the shops. 



373. "We know but little as to the germination of the 

 spores and the subsequent development of the vegetative 

 filaments. 



Practical Studies.- — (a) Collect a few toadstools in various stages 

 of development, securing at the same time some of the subterranean 

 vegetative filaments. Note the appearance of the young spore-fruits, 

 and how they develop into the mature toadstool. 



(6) Select a mature (but not old) spore-fruit with dark-colored 

 spores, cut away the stem, and place the top (pileus) on a sheet of 

 white paper, with the gills down. In a few hours many spores will 

 be found to have dropped from the gills upon the paper. 



(c) Examine the minute structure of various parts of the spore- 

 fruit and the vegetative filaments, and observe that they are com- 

 posed of rows of cylindrical colorless cells joined end to end. 



{d) Make very thin cross-sections of several of the gills and care- 

 fully mount in water or alcohol. Note the layer of spore-bearing 

 cells (hymenium), with spores borne upon little stalks, as in Fig. 118, 

 F/and VII. 



Systematic Literature. — Saccardo, Sylloge Fungorum, 5, 6. 



Class 8. CHAEOPHYCE.ffi. The Stonewoets. 



374. The plants of this class are small green aquatics 

 with jointed stems bearing whorls of leaves (Fig. 119). 

 Both stems and leaves are very simple, being often no more 

 than a row of cells, but sometimes a cylindrical mass of 

 cells. The sexual organs occur upon the leaves. They 



