56 OUTLINES OF BRITISH FUNGOLOGY. 



necessarily founded on slight variations of structure, and the 

 same species in different stages of growth might sometimes be 

 referred with equal propriety to three or four genera. The 

 transitions, for instance, from gills to folds, from sinuses 

 arising from the union and ramification of gills to regular 

 tubes or pores; and again, when these are broken up, from 

 mere walls of pores, to teeth, warts, graimles, etc., are almost 

 infinite. Undoubted Agarics, for instance, may be found 

 where the veins which connect the gills arc so abundant and 

 prominent that it is scarcely possible for the tyro to believe 

 that he has an Agaric before him, looking merely to the 

 definition of the genus. Indeed, there is an abnormal condi- 

 tion of the gills of many Agarics, where an hymenium is pro- 

 duced on the top of the pileus as well as beneath, in which 

 the character of gills is quite lost. Such conditions have been 

 found in A. rubescens, A. odoriis, A. cenissatus, A. campestris, 

 A. laccatus, and some others, and very puzzling they are to 

 beginners. 



Amongst the naked-seeded or sporifcrous Fungi, the fruit 

 varies but little ; but in the sporidiiferous species the modifi- 

 cations of the sporidia in size, form, number of septa, etc., is 

 often A'ery great ; insomuch that there is a disposition amongst 

 many fungologists to undervalue microscopic characters. 

 They are, however, of very great value, if the changes which 

 they are liable to undergo in passing from infancy to full 

 growth are properly borne in mind : indeed, without them it 

 is utterly impossible to distinguish many species. It is not, 

 however, within my scope to advert more particularly to this 

 subject here. 



There is one more variation of which Fungi are capable, of 

 which it is necessary to add a few words. The hymenium, in 

 the greater part of the vast group of Hymenomycetes, is es- 

 sentially turned away from the light, and we have just seen in 



