. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 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 ca'oadensis^ 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 iirs. One of the cases of infection referred to above was
. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 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 ca'oadensis^ 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 iirs. 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 kiUed, and woven on to the twig by Fig. 88.—Trichosphaeria parasitica. Mycelial cushion on lower side of Fir needle, a. Filamentous mycelium, which, at 6, sends downwards numerous branches to produce a cushion of parallel hyphae, c. Where the mycelium rests on the epidermis, rod-like haustoria are sunk into the outer wall of the epidermal cells, e e; d shows the mycelial cushion slightly detached from the epidermis, so that the haustoria have been withdrawn. /' /, Epidermal cells filled with brown contents, g g, Chlorophyllous mesophyll, which becomes brown after the mycelium has penetrated to it. i. Outer court of a stoma filled by a mycelium with no haustoria, but adhering to the waxy granules of the stomatai aperture. (After R. 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, the Alps, Bavarian forests, the Black Forest, etc. On dry airy situations, on free-standing trees, and on the highest branches of a tree, it is rarely present. ^ V. Tubeuf, Beitriige z. Kenntn. d. Bamnkrankheiten, Berlin (Springer), 1888. "v. Tubeuf, "Trichosphaeria parasitica der ; Botan. Oent
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