104 PRACTICAL EOT AN r. 



A comparison may be made with Coprinus micaceus : this 

 Fungus appears almost with certainty if cow-clung be kept for 

 three or four weeks at a moderate temperature under a bell-glass : 

 if sections be cut from the lamellae, the structure of the hymenium 

 will appear similar to that above described, but the number of 

 sterigmata on each basidium is four. On species of Coprinus 

 large bladder-like cells (cystidia) are found projecting from the 

 hymenial layer. 



Examine specimens of other Hymenomycetous Fungi, e.g. 

 species of Polyporus, Dcedalea, Boletus, and Hydnum: note in 

 them the difference of conformation of the thallus, and especially 

 of the hymenial surface ; also the difference of texture : thus in 

 Dcedalea quercina, and in some species of Polyporus, the thallus 

 is hard, and of a corky or woody nature, while in others (e.g. 

 Polyporus giganteus) it is soft and succulent. 



Sections should be cut from the thallus of Dcedalea quercina, 

 or some other woody form : an examination of them will show 

 that, though the thallus is hard, the structure of it is similar to 

 that of the mushroom, the whole being composed of branched 

 septate hyphae. 



Sections should also be made through the hymenium of some 

 species of Polyporus in such a way as to cut the pores transversely : 

 examination of these will show the hymenial layer lining the 

 pores, and consisting, as in the mushroom, of paraphyses and 

 basidia, the latter producing sterigmata and spores ; but in 

 Polyporus the hymenial layer is less closely packed and regular. 



A comparison should also be made of some types of the Gastero- 

 mycetes, e.g. Lycoperdon, Geaster, Crucibulum, and Phallus. In 

 these forms it will be seen that there is considerable variety in 

 detail of arrangement of the hyphse, resulting in a marked differ- 

 ence of external conformation of the mature Fungus. Still, sections 

 of them in relatively young stages will show that they also are 

 composed of branched and septate hyphse, while the mode of 

 formation of the spores on the basidia of more or less regular 

 internal hymenial layers, corresponds essentially to that already 

 described for the mushroom. 



