INTRODUCTION TO CETPTOGAMIC BOTANY. 357 



which this vast collectioa of plants is composed, are connected 

 so intimately with one another, and the whole mass is so 

 natural, that it is scarcely possible to say where one genus 

 ends and where one begins. Practice alone, and tact, can do 

 this in the more difficult cases ; and it must be confessed that 

 in different states the same species is often positively referable 

 to three or more distinct genera, and it is only the possession 

 of intermediate, states which can put one in a condition to say 

 which is the correct nomenclature. This, however, is not a 

 question parallel with that which is so often quoted amongst 

 the OrchidecB, but the difficulty arises from the very nature of 

 the case. If pores, gills, and prickles alone were produced, 

 no difficulty would arise ; but the gills are branched or con- 

 nected by veins tiU they assume the appearance of pores ; and 

 the walls of the pores are split and broken up till they assume 

 the guise of prickles. In consequence there will always be 

 some doubt about certain species of Dwdalea and Irpex, 

 though there is none about the generic distinction of the more 

 typical species ; and if some difficulty arise even where there 

 is great diversity of substance, how much more between such 

 Fungi as Lenzites and Dwdalea, which agree in substance, but 

 which typically belong to two distinct series. 



388. The first group, then, consists of those species in which 

 the hymenium is absolutely even, except so far as it follows the 

 inequality of the matrix, or has merely faint raised points or 

 lines disposed without any definite order over the hymenium. 

 From the very nature of the case they are inclined to assume 

 a radiating form ; but no one could take them for gills, except 

 possibly in some states of Guepinia. Cyphella is as essentially 

 cup-shaped as any Peziza, and the only difference that exists 

 between them is the non-production of ascL The genus, though 

 consisting of obscure species, is of great importance, as con- 

 necting Porothelium, and thence Polyporus, with Peziza. 

 Craterellus, again, assumes a pileate form, and is only distin- 

 guished from Cantharellws by the indistinctness of the folds 

 of the hymenium. In Craterellus lateritius, Berk., which is 

 Thelephora Cantharellus, Schwein., the veins are so distinct as 

 rather to give the notion of a common Chantarelle imperfectly 



