290 ASCOMYCETES. PART n. 



rain water holds in solution nitrates and ammoniacal 

 salts together with salts of potash and lime, and M. 

 Barral has ascertained the existence of phosphates also. 

 M. Barral found that the nitrates and ammonia disappear 

 under the influence of cryptogamic plants. 5 



In the genus Oidium, belonging to the Mucedines, 

 the short threads have a string of spores, like a necklace 

 of beads, on their tops. Species of this genus are found 

 on damp paper and honeycombs; also on decayed oranges, 

 and other spoilt fruits. 



The family of the ASCOMYCETES produces spore-bear- 

 ing cells, called sporidia, enclosed in long cylindrical 

 sacs or asci, in the definite numbers two, four, eight, 

 sixteen, thirty-two, &c. The great characteristic of this 

 large group, consisting of six orders, is the fleshy soft 

 texture and the more or less complete exposure of the 

 fructiferous surface. In one division the asci are per- 

 sistent ; this includes the Elvellacei, the Tuberacei, the 

 Phacidiacei, and the Sphseriacei. In the other division 

 the asci are often evanescent, and this includes the 

 Perisporiacei and the Onygenei. 



The genera Peziza and Helvella are the principal 

 fungi belonging to the order Elvellacei. The Pezizee 

 are a very numerous race, and consist of brilliantly 

 coloured little cups, with or without stems, and more or 

 less concave. They grow in the cooler part of the tem- 

 perate zone, many show themselves in spring, and some 

 of the largest and most beautiful appear during . the 

 melting of the snow. 6 A few are subterranean, and 1 28 

 species inhabit Great Britain, many growing on the 

 ground, others on stumps of trees, dead sticks and tim- 

 ber, on living plants, damp walls, &c. They are sin- 

 gularly beautiful, including ' many of the most elegant 



5 ' Comptes rendus,' Nov. 12, I860. 



6 ' Geographical Distribution of Fungi,' by M. Fries. 



