ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 481 



tained by the stigmatic hairs or in the groove of the seed. In all the 

 cases examined the mycelium was never found to penetrate into the 

 albumin or embryo unless the cutinized and sclerified layer present is 

 ruptured. Beauverie holds that the uredospores can pass the winter 

 much better within the seed than when free. He formulates various 

 hypotheses to account for the method in which the seedling could be 

 infected by these spores. He favours the idea that the dissemination of 

 the spores is brought about by the rupture of the seed-coverings during 

 the germination of the seed. He indicates certain experiments which he 

 intends to perform to establish whether the spores are really capable of 

 retaining their capacity for germination, and also the method of infec- 

 tion of the young plant. 



Mycoplasm.* — J. Eriksson has given a result of his studies on 

 I 'romijres Betse. His paper begins with an historical account of the 

 knowledge of the fungus. The author found that where beetroot was 

 attacked by the disease the latter is very unequally distributed over the 

 field, and that in the case of neighbouring plants one may be diseased 

 and the other healthy, this condition continuing until the roots are 

 gathered. The fungus is autcecious, but during his experiments Eriksson 

 did not find the secidium stage, and therefore concludes that infection 

 did not take place by means of teleutospores. To gain some idea of 

 how the fungus survived the winter, five roots severely attacked and 

 five roots slightly affected were taken in autumn, washed, the old leaves 

 removed, and the roots planted. The following spring they were cleaned 

 afresh. On the young leaves of one of the plants which had been badly 

 attacked the rust appeared, and shortly afterwards all were attacked. 

 No diseased plants were in the neighbourhood of Stockholm where the 

 experiments were conducted, the author stating that the normal distribu- 

 tion zone ends a degree of latitude south of that place. Various reasons 

 are given for believing that the fungus exists throughout the winter in 

 the interior of the beetroot, not as a mycelium, but as a latent plasma 

 (" mycoplasma ") within the cells, probably at the top of the root from 

 which it penetrates into the young leaves. Microscopic examination of 

 various parts was made, but only in one case was any trace of mycelium 

 found. 



Artificial Cultures of Basidiomycetes.t, — V. H. Young has suc- 

 ceeded in growing Cltiocybe Uludens in pure culture. Spores of the 

 fungus were obtained and dilution cultures made on beef-malt-agar 

 medium. The spores germinated readily, and in. the course of three 

 or four days numerous separate colonies appeared on the agar surface. 

 These were transferred to sterile culture tubes of the same medium. 

 Vigorous growth took place, and the tubes soon displayed thick felts of 

 a brownish-white mycelium. Eventually mature fruiting bodies arose 

 developing quite normally except for their size and the "re-curved" 

 condition of the pilei. Examined microscopically the fruit-bodies were 

 found to be sporulating profusely, giving rise to spores which were quite 



* Bev. G6n. Bot., xxv. bis (1914) 247-58. 

 t Bot. Gaz., lvii. (1914) pp. 524-6. 



Oct. 21st, 1914 2 K 



