INTRODUCTION TO CRYrTOOAMTC BOTANY. 285 



glum, it is usually of a brighter colour than the walls, the con- 

 trary to which obtains in Pezisce. The greater number grow 

 on wood or dead vegetable productions; but a few, as Lahrella 

 rtamiicce, occur on living leaves. The whole plant in this 

 case seems to be traversed by the mycelium ; for if a plant 

 thoroughly infested by it be taken to a distance, it produces 

 for some years in succession a fresh harvest, even in countries 

 where the species is unknown in a wild state. This was the 

 case with plants brought by me from Lille, in 1837. Cor- 

 dierites approaches in form to some Hymenomycetes, and may 

 be compared with Guepinia. Phacidiacei abound in many 

 parts of Europe and America, but are rare elsewhere. Gor- 

 dierUes is the only form peculiar to the tropics or sub-tropics. 

 A species was found by Sj^ruce on the Rio Negro, a tributary of 

 the Amazon, nearly allied to Peziza irregidaris, Schwein, 

 which appears to belong to the same genus, and to affect the 

 highest latitude of any known species. Glonium occurs not only 

 in several of the North American states, as far down as South 

 Carolina, but I have specimens from Sweden. New Zealand 

 has one or two species in common with the warmer North 

 American provinces, or even with Surinam. Stylospores, 

 accomj^anied sometimes by spermatia,* occur in some of the 

 sj^ecies. In Tymipanis (Fig. 60, c) two modes of fructification 

 have been seen in the same hymenium, the one resembling 

 Dlplodia, the other consisting of asci, containing an indefinite 

 munber of sporidia, and it is probable that in such species there 

 are also asci containing a definite number of sporidia. The 

 asci of Aylographum are remarkable for being very short 

 and nearly globose. The old Hysterium rugosura (Dichaena) 

 assumes a multitude of forms with very different fruit, and it 

 is probable that all of these are mere modifications of one com- 

 mon species. The species are in general far too small to present 

 any article of food, and I know of no useful purpose to which 

 any of them are applied. 



5. TUBERACEI, Fr. 



Hypogeous. Hymenium mostly convolute, and, by conflu- 

 ence, forming veins in which the asci are irregidarly distributed. 

 * Tul. iu Auu. d. Sc. Nat., scr. 3, v. 20. 



