422 SUMMABY OF CURRENT RESEARCHES RELATING TO 



Thelephora laciniata is injurious to conifers from one to two years 

 old, attacking especially Pinus montana and Picea excelsa. 



Corticium comedens often attacks and kills young oaks and alders. 



Of the Gymnoasci which form the " witch-brooms," JExoascus is 

 especially described on various species of Prunus, E. Carjpini on the 

 hornbeam, and Taphrina hetuUna n. sp, on the birch. The colourless 

 branched mycelium of the last species penetrates the branches and 

 leaves, forming on the under side of the latter a mealy coating com- 

 posed of the asci (about 45-55 /x long and 20 /x broad ; in which are 

 numerous ovate or elongated spores, about 5-7 /u, long and 3-4 [x 

 broad. 



Peziza Willkommi has attacked a large number of young trees in a 

 larch plantation. A few inches above the ground the bark assumes a 

 red colour, and is covered with numerous whitish warts, the spermo- 

 gonia of this fungus, containing a quantity of extremely small 

 elliptical and slightly curved spermatia. The apothecia are developed 

 somewhat later, a little higher on the stem. Beneath the coating of 

 spermogonia the cambium-layer is entirely destroyed. 



Lophodermium pinastri, which is exceedingly destructive to the 

 Danish pine- woods, is treated at length, and is shown to be the cause of 

 the disease known in Denmark as " Schiitte." The leaves of trees from 

 one to two years old are permeated by the colourless, branched and 

 unseptated mycelium, causing them to turn brown. The spermogonia 

 appear at the same time in great numbers on the cotyledons and 

 primary leaves of the main stem, as black elongated, or slightly 

 curved lines. They are filled with numerous rod-shaped spermatia, 

 6-8 fx long and about 1 /x, broad. They always precede the formation 

 of perithecia. It is most destructive to Pinus austriaca. 



Another species, Lophodermium hrachysporum n, sp., attacks Pinus 

 Strohus. The perithecia are smaller than in the last species, and are 

 placed in a single row on the under side of the leaves, often while 

 they are still green. The asci are 100 /x long and 20 /x broad ; the 

 spores 20-25 /x long and 4 /x broad, and are surrounded by a gelatinous 

 envelope. On P. austriaca is also found another species, L. gilvum 

 n. sp., with very small oval pale-yellow perithecia, inclosing paraphyses 

 80-85 IX long, and asci 75-80 ix long and 10-12 [x broad, each of 

 which contains eight long filiform spores. 



Hypoderma sulcigenum n. sp. is an ascomycete, producing on 

 Pinus sylvestris and montana a similar appearance to that of Lopho- 

 dermium pinastri. It appears locally on the leaves, producing brown 

 spots and streaks ; the perithecia are black and linear, from 1-5 lines 

 long, and open by a longitudinal crevice. They inclose filiform 

 paraphyses and club-shaped asci 75-85 fx long and 12 fi broad, each 

 containing four club-shaped spores, 30-40 fx long and 4 fx broad, at the 

 thickest part, inclosed in a gelatinous envelope which is coloured a 

 beautiful bright green by iodine. The mycelium, which permeates 

 the leaves, is colourless, much branched, and unseptated. It is probably 

 identical with Link's Hypodermium sulcigenum. 



Mysterographiwn Fraxini is destructive to ash-trees from 6 to 

 10 feet high. Fawn-coloured depressed spots appear on the stem, 



