ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 67 



Relation of Temperature and Humidity to Infection by certain 

 Fungi. — A long series of experiments has been made and recorded by 

 J. L. Lauritzer {Phytopathology, 1919, 9, 6-35) bearing on this 

 subject. With regard to temperature, he finds very definite limits for 

 infection, which vary according to the fungus. The range for Fuccinia 

 graminis Tritici is between 42° and 53° F. ; for Ascochyta Fagopyrum 

 from 45° F., though there is variation within these limits and 59°, 

 and the highest possible temperature for that fungus is 100° ; the 

 buckwheat plants themselves are killed then. The limits of humidity 

 vary roughly from 90 to 100 p.c, but just how the spore obtains the 

 necessary amount of moisture remains an unsolved problem. The 

 absorption may be from the host-plant or in the depressions of the leaf- 

 surface, especially over the stomata, there may be reserves of humidity. 

 Hairs, in checking evaporation, seem to further the germination of the 

 spores. A. L. S. 



Effect of Salts on the G-rowth of Wine-yeast. — An experimental 

 study of this subject has been made by S. K. Mitra {Univ. California 

 Fubl. Agric. Sci, 1917, 3, 63-102) in the line of similar experiments 

 made with animals, bacteria, etc. The salts employed were the chlorides 

 of potassium, magnesium, calcium, and sodium. Each of these salts 

 alone is more or less toxic to the yeast Saccharomyces ellipsoideus at 

 certain concentrations, though at low concentrations they stimulate 

 growth. The salts used had a marked effect on the size and appearance 

 of the yeast. The results of the experiments are entirely different from 

 those found with bacteria or with the higher plants and animals. 



A. L. S. 



Varietal Susceptibility of Beans to Strains of Colletotrichum 

 Lindemuthianum. — Mortier F. Barrus {Fhytopathology, 1918, 8, 

 589-614, 5 pis.) has carried out a series of inoculation cultures on 

 various host-plants, which tend to show tiiat several species of Fhaseolus 

 and other allied plants may become infected with the fungus but are not 

 to be reckoned as favourable hosts. He tLinks there may be some factors 

 connected with the parasite as well as the host that more or less inhibit 

 growth. A. L. S. 



Biology of Sand-dune Fungi. — E, M. Wakefield {Trans. Brit. 

 Mycol. Soc, 1918, 6, 33-6) notes the peculiar and large fungus-flora 

 observed by Wheldon on the Lancashire dunes, and by herself on the 

 Gower Coast, South AVales. Some of the species were evidently asso- 

 ciated with the dune grasses ; others, especially Bolbitius tener and 

 Galera rubiginosa, grew on the sand, and evidently subsisted on a crust 

 of green and blue-green algse which permeated the sand. A. L. S. 



Fungus from Weybridge. — E. M. Wakefield and A. A. Pearson 

 {Trans. Brit. Mijcol. Soc, 1918, 6, 68-74, 6 figs.) publish a series of 

 resupinate Basidiomycetes which includes six species and two genera new 

 to Britain, with one species, Talasnella tremelloides, new to science. They 

 were found during the winter months at Weybridge, Surrey. Froto- 

 dontia and Coniophorella are genera new to Britain ; the species 

 G. olivacea has been included as Coniophora olivacea in British lists, but 

 this is the first tim.e it has bten correctly identified. A. L. S 



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