ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 589 



•species of Mucor which he cultivated with a view to their ultimately 

 forming yeasts. The first of these methods has given as yet no certain 

 results. With the cultivation of Mucor he has been moro successful. 

 By growing the fungus in successive liquid cultures he produced an 

 Oidiurn from the hyphae, and from the Oidium he obtained yeast-cells 

 which grew plentifully, and induced considerable fermentation. Winkler 

 found that a solution containing honey was best adapted for the final 

 growth of the yeast-cells. Ho did not, however, succeed with all the 

 species of Mucor that he experimented with. He concludes with a com- 

 parison of the 3Iucor-oidium spores and the resting spores of yeast, 

 whicli he considers bear a strong resemblance to each other. 



Actinomucor repens.* — Wl. Schostakowitsck has discovered and 

 described this new fungus, a genus of the Mucoracese. It is charac- 

 terised by " runners," which resemble somewhat those of Bhizopus and 

 Alsidia, but it differs from these genera in the formation of the columella 

 and sporangiophore. At the end of the runners there rise groups of 

 sporangiophores ; these branch usually twice in a verticillate manner, 

 each branchlet terminating in a sporangium. In addition there are 

 formed occasionally sporangiophores on the " runners," which are single, 

 or terminate in a crown of short branches. The sporangia terminating 

 the main branches are larger than the others ; the columella is- conical, 

 that of the smaller sporangia is almost round. The spores are globose, 

 about 7 fL in diameter. They are colourless, but appear black in the 

 mass. The fungus was found on pigeon's dung. Its form varies some- 

 what on different substrata. 



Clasterosporium carpophilum (Lev.) Aderh. t — R. Aderhold 

 publishes the results of his studies and researches on the fungi that 

 cause gummosis of trees with stone-fruit. He finds that the various 

 species of Clasterosporium found on these trees are identical. Cultures 

 were made of the fungus, and every means tried to find some higher 

 form of development, but in vain. The parasite evidently passes the 

 winter in the wounds caused by gummosis, and on the young^twigs. 

 The writer considers it to be identical with Coryneum Beijerinclcii. He 

 discusses the probability of Clasterosporium being the cause of gummosis. 

 The malady was always induced by infection with the spores of the 

 fungus, though other causes might also be at work. After infection the 

 cambium-cells were excited to abnormal growth. Aderhold concludes 

 that the fungus secretes a ferment which acts on the cells of the host- 

 plant, thereby inducing unnatural activity. The fungus was rarely 

 found in the swollen tissue or in the cambium. 



Erysiphe Grraminis.t — Em. Marchal gives the results of his experi- 

 ments on the spores of this fungus. He desired to find out if the 

 spores collected from one host would infect indiscriminately any of the 

 other plants on which that species is recorded. He selected plants of 

 wheat, and on these he planted Oidium spores of E. graminis, taken 

 respectively from plants of wheat, barley, rye, and oats. The first only 



* Zeitschr. angew. Mikr., viii. (1902) pp. 35-8. 



t Arb. ;ms der biolog. Abt. fur Land-u. Forstwirtlisch. am Kaiserl. Gcsundbeits., 

 ii. (1902) p. 515 (2 pis.). See also Bot. ZeiU lx. (1902) p. 2 

 % Comptes Rendus, exxxv. (1902) pp. 210-2. 



October loth, 1902 2 R 



