Uncinula 105 



were placed in the autumn in sacks on the open ground. Although 

 the appendages of the perithecium soon disappeared, the asci and 

 spores underwent little change until the end of December, when 

 many of them were found to be dead or more or less collapsed. 

 All attempts to germinate the ascospores before January failed, 

 and it was only after repeated trials through February and ]\Iarch 

 that success was attained. The perithecia were from time to time 

 removed from the leaves and placed In a drop of sterile water in 

 Van Tieghem cells. In one instance, which may be taken as 

 typical of the usual development, some perithecia were placed in 

 cells on January 7th. Twenty days later no change had taken 

 place, the cell having been kept free from jars. The cell was then 

 placed under the microscope, and gently jarred with a needle, 

 whereupon one of the perithecia suddenly burst and the ascI 

 escaped into the surrounding water. The first ascus was violently 

 ejected from the perithecium to a distance equal to about twice 

 the length of the former. This was immediately followed by a 

 second and a third ejected in the same way. The ruptured wall 

 of the perithecium then closed and no more asci escaped. No 

 sooner were the asci free than their spores began to escape or else 

 to break up within the ascus. In the former case they escaped 

 from the top, side or bottom of the ascus. A large part of the 

 spores burst as soon as they were set free. Nearly all the spores 

 that failed to burst began to send out germ tubes in four or five 

 hours, and at the end of twelve hours the tubes had reached a 

 length twice that of the spore or more. A number of attempts 

 were made to infect leaves with ascospores, but the results were 

 in every case negative. 



6. U. ciRCiXATA Cooke & Peck 



U. circinata Cooke and Peck, Journ. of Bot XL 1:12. 1872 ; 

 Peck, Trans. Albany Inst, 7 : 214. / 7"^- 1^72; Peck, Reg. 

 Rep. 25: 96, 1873; Sacc. Syll. Fung, i: 8. 18S2; Burr and 

 Earle,BulL III State Lab. Nat. Hist. 2 : 408. 1S87; Burr. ; E!l. 

 5c Everh. N. Amer. Pyren. 17. 1892. 



Exsicc: Ell. N. Amer. Fung. 4^7; ^e Thum. Myc. Univ. 

 2051; Roumeg. Fung, select, exsicc. 49^7; El^- ^"^ ^verh. 

 Columb. Fung, no; * Seym, and Earle, Ecqh. Fung. 115, 116. 



