470 SUMMARY OF CURRENT RESEARCHES RELATING TO 



verse 4-soptata loculis imo vcl duobus soptis longitudinalitcr divisis ; 

 C. Sporidia transverse 3-5-septata ; D. Sporidia transverse semper 

 5-scptata ; E. Sporidia transverse G-7-septata ; F. Sporidia transverse 

 8-pluri septata ; G. Sporidia hyalina. 



Trichosphaeria paradoxa and Herpotrichia nigra.* — HcrrR. Ifartig 

 givos some further particulars respecting these two parasitic fungi 

 parasitic on Conifers. 



Trichosphseria paradoxa attacks almost exclusively Abies pectinata. 

 The pseucloparenchymatous mycelium puts out a number of rod-like 

 haustoria, which penetrate the cuticle, but do not actually enter the 

 epidermal cell. These haustoria exude a ferment which kills the 

 adjacent mesophyll-cells ; and a number of hyphre then enter the leaf 

 through the stomata, completely killing it. The ripe spores are usually 

 divided into four, sometimes into only two or three compartments, or are 

 rarely undivided. 



Herpotrichia nigra is parasitic on Picea cxcelsa, Pinus montana, and 

 Junipcrus communis and nana. The dark-brown granular mycelium also 

 puts out haustoria into the cuticle. The asci are large, 7G-100 /x long 

 and 12 /x wide; they contain eight ascospores, each of which is con- 

 stricted and septated in the middle. 



Taphrina-t — Herr C. J. Johanson has made a careful study of the 

 twenty-one species of Taphrina Fr. (Exoascus Fkl.) known in Sweden, 

 five of which have not been found outside the Scandinavian peninsula. 

 The character hitherto considered common to the genus, of producing a 

 hibernating mycelium, he finds to be not universal; an exception is 

 furnished by T. carnea ; and probably also by T, Sadebechii, parasitic on 

 the leaves of Alnus glutinosa, and by T. Betulse. 



The following new species are described : — T. alpina, and T. bacterio- 

 sperma on living leaves and branches of Betula nana. The former of 

 these species produces the deformation known as " witch-broom," while 

 the latter does not. The latter is the only species which extends into 

 Greenland. T. rhizophora Johans. (Exoascus aureus Sad.) is distinguished 

 by the absence of pedicel-cells, and by the asci having yellow contents, 

 and putting out a long narrow root-like portion into the tissue of the 

 host. It occurs on the fruit of Populus alba and tremula, causing them 

 to become deformed and covered by a yellow bloom. 



Character of the Injuries produced by Parasitic Fungi upon their 

 Host-plants, i; — Mr. A. B. Seymour discusses the various ways in which 

 parasitic fungi injure their host-plants. 



Firstly, they deprive them of nourishment ; this is by far the most 

 important and general injury which is produced upon plants by parasitic 

 fungi. (2) While the food supply of the plant is reduced, its power to 

 replenish it is at the same time impaired, i. e. in case the fungus grows 

 upon the green parts, as it does most frequently. (3) Growth may be 

 abnormally accelerated or retarded, and both these eifects may be pro- 

 duced in different cases by the same fungus, thus causing distortion; 

 (4) not only green parts are affected, but roots, stems, inflorescence, 

 flowers, and fruit ; (5) leaves and fruit when diseased fall prematurely. 



* Hedwigia, xxvii. (1888) pp. 12-5. Cf. this Journal, 1886, p. 298. 

 t Naturv. Studentsallsk. Upsala, April 28, 1887. See Bot. Oentralbl , xxxiii. 

 (1888) pp. 222 et scq. Cf. this Journal, ante, p. 274. 

 % Amer. Naturalist, xxi. (1887) pp. 1114-7. 



