122 FUNGI. 



tions which the form and colour of the spores undergo in dif- 

 ferent species, as this has already been alluded to. The spores 



Pig. 46*.— [a) Spore of Gomphidim Fig. 47.— Spores of (a) Polypmus cassius : 

 viscidus: (6) spuro of Coprinus micaceus. (b) Boletus parasiticus; (c) Hydmim. 



in the Polyporei, Hydnei, &c., are less variable, of a similar 

 character, as in all the Hymenomycetes, except perhaps the 

 Tremellini. 



When an Agaric is mature, if the stem is cut off close to the 

 gills, and the pileus inverted, with the gills downwards on a 

 sheet of black paper (one of the pale-spored species is best for 

 this purpose), and left for a few hours, or all night, in that 

 position, the paper will be found imprinted in the morning 

 with a likeness of the under side of the pileus with its radiating 

 gills, the spores having been thrown down upon the paper in 

 such profusion, from the hymenium, and in greater numbers 

 from the opposed surfaces of the gills. This little experiment 

 will be instructive in two or three points. It will illustrate the 

 facility with which the spores are disseminated, the immense 

 number in which they are produced, and the adaptability of the 

 gill structure to the economy of space, and the development of 

 the largest number of basidiospores from a given surface. The 

 tubes or pores in • Polyporei, the spines in Hydnei, are modifica- 

 tions of the same principles, producing a like result. 



In the Qasterontycetes the spores are produced in many cases, 

 probably in most, if not all, at the tips of sporophores ; but the 

 hymenium, instead of being exposed, as in the Hymenomycetes, is 

 enclosed within an outer peridium or sac, which is sometimes 

 double. The majority of these spores are globose in form, some 

 of them extremely minute, variously coloured, often dark, nearly 

 black, and either externally smooth or echinulate. In some 

 genera, as Enerihenema, Badhamia, &c, a definite number of 

 spores are at first enclosed in delicate cysts, but these are excep- 



