TRICHOSPHAERIA. 



197 



asci, the latter with eight four-celled light-grey spores, which 

 germinate directly and distribute the fungus over new host- 

 plants. 



I found this same fungus on Tsuga canadensis ^ at Baden- 

 Baden, and on spruces in several parts of the Bavarian forests.- 

 It, however, rarely attacks spruces, although they often occur 

 in the same forest with firs. One of the cases of infection 

 referred to above was caused by the diseased branch of a fir 

 lying in contact with a twig of the spruce, so that the mycelium 

 grew from the one to the other ; the spruce needles were killed, 

 and woven on to the twig by hyphae. 



Fic. S8. — Trichospkaeria parasiliai. Mj-celial cushion on lower side of Fir 

 needle, a, Fil.amentous mycelium, which, at d, send.s downwards numerous 

 branches to produce a ciisliioi] (.f jiaiullel hyphae, c. Where the mycelium rests 

 on the epidermis, rod-like hausturia arc sunk into the outer wall of the epidermal 

 cells, e e; d shows the mycelial cushinn slightly detached from the epidermis, so 

 that the haustoria have been withdniwn. .//, Epidermal cells filled with brown 

 contents. </ </, Chlorophyllous mesophyll, which becomes brown after the 

 mycelium has penetrated to it. ?, Outer co\irt of a stoma filled by a mycelium 

 with no haustoria, but adhering to the waxv granules of the stomatal aperture. 

 (After K. Hartig.) 



In woods of young silver fir naturally regenerated, this fungus 

 causes great damage by killing numerous twigs. It occurs every- 

 where in young fir forests, c.f/. the Alps, Bavarian forests, the 

 lUack Forest, etc. On dry airy situations, on free-standing 

 trees, and on the highest branches of a tree, it is rarely present. 



1 V. Tubeiif, Beitrdge z. Kennhi. d. Baumkrankheiten, Berlin (Springer), 1888. 

 -v. Tubeuf, " Trichosphaeria parasitica der Fichte." Botan. CentraUAatt , 

 XLi., 1890. 



