184 



BOTANY 



FIG. 149. A, Clavaria cristata. (Natural size.) S, 

 Hydnum ramosum. C, Polyporus sp. D, underside of 

 C, enlarged to show the pores. E, F, Fames annosus. 

 E, conidia; F, hymenium, with basidia. {E, F, after 

 BREFELD.) 



When the fruit is complete, there is, in Coprinus, a very rapid elonga- 

 tion of the stalk, due to absorption of water and great stretching of the cells. 



The cap, which is 

 closed up, opens like 

 an umbrella, the gills 

 p. splitting from the out- 



side and flattening out 

 very much like the silk 

 between the ribs of an 

 umbrella. The ripe 

 spores are quickly 

 shed, and the whole 

 fruit collapses into a 

 structureless, almost 

 liquid mass. 



Psalliota campes- 

 tris. The common 

 Mushroom (Fig. 148) 

 differs in some respects 

 from the form just 

 described, and is per- 

 haps more typical of 

 the family. The young 

 spore-fruit is more 

 solid than in Coprinus, 

 and the formation of 

 the cap takes place somewhat later. The gills are developed within a cavity 

 which is only exposed when the spores are ripe. A longitudinal section through 

 the young Mushroom shows two small cavi- 

 ties, which are really sections of a single 

 circular canal, which separates the cap from 

 the stalk. Almost completely filling this 

 canal are the young gills, covering the lower 

 face of the cap. At first the cap is no 

 broader than the stalk, with which its mar- 

 gin is connected by a continuous layer of 

 tissue the Velum. As the lateral growth 

 of the cap continues, the velum is finally 

 torn away and the gills are exposed. The 

 remains of the velum surround the upper 

 part of the stalk like a collar, while frag- 

 ments of the velum may often be seen 

 fringing the margin of the cap. 



The Agaricaceae are the largest 

 family of Fungi, including nearly five 

 thousand species. Many of them are 

 among the most valuable of edible 

 Fungi, such as the true Mushroom 

 (Agaricus \_Psalliota~\ campestris), the 

 Chanterelle (Cantharellus cibarius), 

 and many others. On the other ATKINSON.) 



FlQ . 150 . _ 



(After 



