2U 



ASCOMYCETES. 



active vegetation begins about two and a half months later than 

 in the plains, i.e. at the beginning of June. The season of 

 mature spores of Sphaerella is thus delayed till about the 

 middle of August. On 26th September I found at this elevation 



only a few spots on the larch needles, and 

 on these hardly any conidial cushions. By 

 28th September this larch plantation was 

 already under snow." 



" It will thus be seen, that while at a 

 high elevation the larch can flourish with 

 a vegetative period extending only to three 

 and a quarter or four months, the Splw.crdla 

 has not the time necessary for its develop- 

 ment, so that the larch, though much 

 handicapped, remains healthy. Similarly 

 with the larch in Siberia, it grows there, 

 FIG. ioo.-Eniarged asci. as in the mountains, very slowly, yet this 



a Immature asci without , i i -, >; 



parasite can no longer reach it. 



Sphaerella fragariae Tul. Strawberry 



paraphyses, as on April 30. 

 '/. Mature asci, from one of 

 which the spores are escap- 

 ing, as on June 1. x j^-. 

 (After R. Hartig.) 



leaf - blight. 1 In summer free conidia 



(Eamularia Tulasnci Sacc.) and pycnidia 

 are produced, while the perithecia ripen in spring. 



[This destructive disease of the strawberry has been recorded 

 from all parts of the United States. It first appears on the 

 upper surface as small reddish spots, which rapidly enlarge, 

 the centres withering and browning. The growth of the plants 

 and the crop-yield is seriously impaired.] (Edit.) 



Sph. gossypina Atks. 2 [Cotton leaf-blight is a disease on 

 leaves of the cotton plant caused by the Cercospora-sta.ge of this 

 fungus. Small reddish spots appear 011 the leaf, enlarge, and 

 become dry whitish spots with a red margin. The conidia 

 are elongated and produced in long chains. The asci contain 

 eight elliptical spores, which are slightly constricted at the 

 septum when mature, one cell being usually somewhat smaller 

 than the other. This disease frequently accompanies that one 

 known as " yellow leaf-blight," or mosaic disease.] (Edit.) 



1 Trelease, Winconsin Exper. Station, 1885. 



Scribner, F. L., Import U.S. J)</,f. of Agriculture, 1887. Plate. Other 

 papers by Arthur, Dudley, and Garman. 



2 Atkinson, Hntfe.tin Torrey Botan. Club, Vol. xvni., 1891. 



