ZOOLOGY AND BOTANY, MICROSUOPY, ETC. 281 



Fungi. 



Contributions to the Life-History and Cytology of Synchytrium 

 endobioticum. — An investigation of tliis fungus has been undertaken 

 by K. M. Curtis (iVe?<; Phytologist, 1919, 18, 90-91), who now publishes 

 \\ preliminary account of her work. It causes a disease of potatoes 

 known as " black wart," which threatens to become very serious. Curtis 

 describes the development of the fungus from its entry into the host by 

 the motile spores, with the reaction on the host plants, the formation of 

 zoosporangia and the liberation of the sporangia. The motile cells 

 liberated are facultative gametes and may forma zygote, or the gametes 

 may directly infect the host without previous fusion ; a sorus is formed 

 in the host cells. Fuller details will be published later. A. L. S. 



Sexuality in Cunninghamiella. — Owen F. Burger {Bot. Gaz., 

 1919, .68, 134-6). The author finds that in this genus of Mucorini 

 there is no sexual dimorphism ; there exists a selective power in some 

 strains to form zygospores with certain other strains ; in some strains 

 there is a condition that might be called hermaphroditism, but in none 

 of them did branches of the same hyphtc conjugate. Zygospores were 

 produced only between strains the gametes of which were compatible. 

 The cultures that led to these conclusions are fully described. A. L. S 



Physoderma Disease of Corn. — W. H. Tisdale (Juur/i. Ayric. 

 Research, 1919, 16, 137-54, 9 pis., 1 fig.). This disease has caused 

 great loss to corn crops along the Atlantic and Gulf Coasts in America, 

 and in the Mississippi Valley. The author identified the parasite as 

 Physoderma Zete-3Iaydis, first described by Shaw as occurring in Bengal. 

 The life-history and development of the fungus have been traced by 

 Tisdale by artificial cultures, by inoculations, etc. The sporangia over- 

 winter on old infected plants and in the soil : possibly they may live 

 there and retain viability for a number of years. Crop rotation and 

 resistant varieties are recommended as a means of controlling the 

 disease. A.L. S. 



Some Phyllachoras from Porto Rico. — T. L. Stevens and Nora 

 Dalby {Bot. Gaz., 1919, 68, 54-9, 3 pis.). Most of the species 

 described and figured are new to science. They are parasites occurring 

 •on the leaves of the higher plants. A. L. S. 



to 



Study of Pyrenomycetes. — J. E. Chenantais {Bull. Soc. MycoJ. 

 France, 1918,, 34, 47-73, 123-36; 1919, 35, 46-98, 113-39, 6 pis., 

 25 figs.). Chenantais in a succession of papers has made a study of 

 classification in various groups of Pyrenomycetes. He discusses the 

 conception and the value of genera and species. He decides that there 

 is no rigid rule iu valuing characters of importance in classification. 

 He passes in review a large number of genera and species, giving minute 

 and detailed descriptions of a number both of genera and species. He 

 has established a new genus of Sordarife — Lasiosordaria with two 

 sections, Lasiosordariella and Lasiosordariopsis. A. L. S. 



