ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 175 



Fungi. 



Rhizopus Rot of Strawberries. — Neil E. Stevens and R. B. 

 Wilcox {U. S. Dept. Agric, Bull. No. 31, 1917, 1-21) have studied the 

 fungi that cause rotting of these berries in transportation. They find 

 that it is often, if not mainly, due to Bhizopus nigricans. The fungus is 

 not able to penetrate uninjured epidermis, but enters readily through 

 wounds in either mature or green berries. Rhizopus does not attack 

 strawberries in the field, nor is it able to grow at low temperatures, so 

 that berries gathered in the early morning are more safely transported 

 than those that have been heated by the sun. 



In a further Bulletin (No. 686, 1918, 1-14) the authors publish 

 further details on the disea'^e. They contrast Rhizopus with Botrgtis, 

 which latter is a field rot. Berries infected with the latter fungus should 

 not be packed ; it is able to grow at low temperatures. A. L. S. 



Notes on Mortierella. — Paul Vuillemin (Bull Soc. Mgcol. France, 

 1918, 34, 41-6, 3 figs.) finds that the type species llortierella pohj- 

 cephala includes another species, M. Le Monnieri sp. n. The author 

 describes in detail all the allied forms, and diagnoses yet another new 

 species, M. Mairei. The latter had a brown coloration, due to the sub- 

 stratum, Ustulina maxima. The Mortierellae frequently take the colour 

 of the support ; thus there is a species, M. nigrescens, in which the spores 

 become brown or chocolate. Another species, with similar morphological 

 characters but remaining always colourless, has been named 31. Bainieri, 

 but is probably the same fungus. A. L. S. 



Origin and Development of the Potato Disease, Phytophthora 

 infestans. — Jakob Eriksson (ArJciv f. Botanik, 1916-17, 14, 1-65, 

 6 pis., 5 figs.) gives an account of the research work done on this disease, 

 and the results attained by the different workers. He then describes 

 his own research on the subject and the conclusions at which he has 

 arrived, which differ very widely from those generally received. After 

 describing the first outbreaks of the disease — in Sweden, between the 

 middle of July and beginning of September — he proceeds to the ex- 

 amination of affected leaves. In these he finds a mycoplasm living in 

 symbiosis with the protoplasm of the host-cell. In time fungus hyphae 

 develop from the mycoplasm, pass out from the cell, and form either 

 an oogonial or an antheridial primordium. Fructification between the 

 oogonia and antheridia follows, and an oospore is formed which does not 

 function as a resting spore, but gives rise at once to two or three 

 hyphae, which pass out of the leaf by the stomata and form the familiar 

 conidia, which act as zoosporangia. Eriksson points out that he has 

 not yet ascertained the origin of the mycoplasm, nor does he know if 

 similar developments take place in the seed-tubers during the spring oi 

 Slimmer months. A. L. S. 



New Brown Aspergillus, Eurotium verruculosum. — The new 

 fungus was found in the laboratory on badly sterilized carrots by 

 P. VuiLLEMiN {Bull. Soc. Mycol. France, 1918, 34, 76-83, 17 figs.). He 



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