ZOOLOGY AND BOTANY, .MICROSCOPY, ETC. 195 



As the fungus is extremely common on all bread stuffs, the authors 

 suggest that it may have some connexion with such diseases as pellagra, 

 " corn-stalk disease " and " horse disease," the causes of which are not 

 yet definitely known. 



Cytology of the Plasmodiophoraceae.*--0. Winge publishes a long 

 paper on this subject, taking in order the following forms : Plasmodio- 

 phora Brasskse, Sorosphsera Veronicse, Ligniera Junci, L. graminis, 

 Sorodiscus Callitrichis g. et sp. n., Spongospora subterranea, Tetramyz 

 parasitica, Glirysopklyctis endobiotica, Asterocystis radicis, Rkizomyxa 

 hypogsea, Woronina polycistis, Pyrrhosorus mari/ius, and Sorolpidium 

 Betse. For each of these he gives not only his own observations but the 

 facts as ascertained by other workers. Special attention is given to the 

 new genus Sorodiscus which forms small round tumours on the stems of 

 CalUtriche vernalis. In the vegetative state it consists of multinucleate 

 myxamcebae, mostly several in each herb-cell : these divide up into 

 uninucleate spores. 



Buteshire Microfungi.f — D. A. Boyd finds that the varied physical 

 features of Buteshire afford conditions exceptionally favourable to the 

 development of the lower orders of Cryptogamia. The list of fungi 

 has been compiled from observations made by various Naturalist Societies, 

 but as the forms are minute and Uttle conspicuous there are doubtless 

 many not yet recorded. The host-plant is given in the case of parasitic 

 fungi, and the locality where they have been found. 



Fungi which cause Plant Disease.^ — F. L. Stevens' book on this 

 subject is a compendium of all the fungi hitherto recorded as being the 

 cause of injury to plants, with special reference to those found in 

 America. " It is intended to introduce to the student the more impor- 

 tant cryptogamic parasites affecting economic plants in the United 

 States." 



Stevens gives in the introductory chapters a general account of 

 fungi, their means of propagation, etc., and then goes on to describe 

 the familar genera and species that are inimical to other plants in due 

 order. These form a large percentage of the whole. Synoptic keys are 

 provided of families and genera, and the species are more or less fully 

 described. In the case of those with a complicated life-history, such as 

 the Uredinege and the Fungi imperfecti, the forms are referred when 

 possible to the perfect stage. The illustrations are abundant and 

 instructive, and copious bibliographies, glossary, and index are provided. 



Diseases of Tropical Plants.§ — M. T. Cook has published a book 

 on this subject, with a view of aiding planters in warm countries to 



* Ark. Bot., xii. No. 9 (1913) 39 pp. (3 pis.). 



t Trans. Buteshire Nat. Hist. Soc., vi. (1913) pp. 78-89. 



X The Fungi which cause Plant Disease, by F. L. Stevens, Ph.D. New York : 

 The Macmillan Co. (1913) ix and 754 pp. (449 figs.). 



§ The Diseases of Tropical Plants, by M. F. Cook, Ph.D. London : Mac- 

 millan and Co. (1913) xix and 317 pp. (85 figs.). 



