Parasitic Fungi of Illinois. 407 



length from once and a half to four or more times the diam- 

 eter of the peritheciurn, colored for more than half their length, 

 frequently septate, occasionally forked, tips loosely and some- 

 what spirally coiled; asci mostly 4-6 (4-8 Farlow) ovate, 

 pedicellate; spores 4-6. 



Amphigenous: mycelium web-like, thin and evanescent; con- 

 ceptacles minute, globose, black ; appendages ten to twenty, in length 

 once or twice the diameter of the conceptacle, simple, obscurely septate 

 toward the base, colored, a little paler at the tips, sporangia four to six, 

 subglobose or ovate containing four to six spores. Peck, 25th Rep. 

 N. Y. State Mus., p. 96. 



On Vitis (cultivated): Union, Oct. 24, 1965, Oct. 28, 2071; 

 Wabash (Schneck); Champaign (Burrill). Ampelopsis quin- 

 quefolia: McHenry, Aug. 20, 1203; La Salle, Sept. 12, 1483; 

 Rock Island, Sept. 21, 1622; Lee, Sept. 8, 5700^; Ogle, Sept. 

 25, 6161; Champaign (Burrill). 



The form on Vitis, which is one of the common "grape 

 mildews," is usually known as U. spiralis, B. & C. Aside from 

 its usually somewhat longer appendages, there seems to be no 

 way of distinguishing it from the previously described form on 

 Ampelopsis. The appendages in each are colored, frequently 

 septate, and similarly coiled at the tip, while the cellular 

 structure of the walls of the perithecium, and the characters of 

 the spores and asci, are indistinguishable. In specimens on 

 Vitis from Massachusetts (Seymour), the appendages are 

 mostly very long; but in the Illinois specimens they are 

 frequently not more than twice, or sometimes only once and a 

 half, the diameter of the perithecium; while on Ampelopsis they 

 are frequently as much as two, two and a half, or even three 

 times the diameter. 



U. macrospora, Peck. 



(Trans. Albany Inst., VII., p. 215.) 



Amphigenous. Mycelium conspicuous, abundant; perithe- 

 cia large, 110-140 /*, wall tissue soft, reticulations very small, 

 5-10 A*, and rather obscure; appendages very numerous, 50 or 

 more, hyaline, slender, smooth, usually shorter than the diam- 

 eter of the perithecium, tip closely coiled, not enlarged; asci 

 several, 8-10; spores 2, large, 20 by 30-35 p. 



