332 INTRODUCTION TO THE STUDY OF TUNC, I 



the United States. Of the remaiuiiig 3 14 the majority will 

 be found inhabiting the temperate zone of the southern 

 hemisphere. Hence this portion of the Discomycetes must be 

 accepted as confined in a remarkable manner to a temperate 

 climate. 



The whole of the Pyrenomycetes, according to the latest 

 enumeration, are not less than 10,478, and of these a large 

 proportion belong to Europe and North America, — probably 

 not so much on account of their actual preponderance in 

 nature, as because of the greater attention which has been 

 paid to their collection and investigation. The distribution is 

 rather unequal in such a large group, some large genera being 

 almost tropical, while others are nearly wholly temperate. For 

 example, the Hjjpocrcaccac are fleshy, and hence a large pro- 

 portion occur in temperate regions. The Dothideaceae and 

 Microthyriaceae, on the other hand, are tropical, or sub- 

 tropical, and so also are some genera of the Sphaeriaceae. 

 This will appear more clearly if we divide the w^hole into 

 subsidiary groups, and first examine into the Perisporiaceae, 

 with about 770 species. These again consist of the Ery- 

 sipheae and the Perisporieae, the latter subtropical, the former 

 temperate. The few species of Erysipheae not found in 

 Europe or North America will be found in temperate Asia or 

 in the temperate zone of the south hemisphere. With the 

 other group it is the reverse, for the European species of 

 Perisporieae are few, and in some genera none, whereas 

 in North America they are found in the southern states. 

 Meliola is really the tropical, or subtropical, analogue of 

 Erysiphe, and with Astcrina, Dimerosporium, and Capnodium 

 rarely found, and only in a depraved state in Southern 

 Europe. 



The Hyjwcrcaceae number nearly 900 species, and these 

 preponderate in temperate regions, but some species extend 

 into the subtropical. The remarkable genus Cordrjceps, the 

 species of which possess a fleshy stroma, growing mostly on 

 dead insects, has some 50 species, of which 14 are European, 

 8 North American, 5 Australian — or 27 temperate against 

 23 subtropical. Again in Hijpomyces, with 54 species, all 

 except six are found in Europe or North America. And also 



