ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 567 



graminis. When the disease attacks the young wheat it destroys the 

 roots and the lower part of the stem, and is popularly described as 

 " take-all." The plant is at other times infected as the cars develop, 

 and the seeds are destroyed. It is then known as " white-heads." The 

 disease has also been detected in Europe. 



Mycorhiza of Epiphytic Plants.*- — H. Jacob de Cordemoy has con- 

 tinued the research commenced on the Vanilla plant in reference to the 

 advantage gained by the roots from symbiotic fungi. He found that 

 the fungus not only lived in symbiosis with the roots of the Vanilla, but 

 that it also penetrated the tree on which the orchid was epiphytic, that 

 it drew sustenance from it, and that, for this reason, the Vanilla grew 

 more luxuriantly attached to a living than a dead support. He has ex- 

 amined in similar fashion three species of Piper, and has found the same 

 conditions existing in them. The roots of the epiphyte are associated 

 with a mycorhiza, fine strands of which traverse the long aerial roots 

 and pass from them into the cork tissue of the supporting plant. Some 

 of the filaments have been observed penetrating the cortical tissue below 

 the cork layer. The growth of the epiphyte is evidently materially 

 assisted by the nutritive material of the host. 



Myxobacteriacese.t — Roland Thaxter, the discoverer of the group of 

 organisms, reviews the work done since his first publication of them in 

 1897. He notes the announcement of Dr. E. Zederbauer that they do 

 not form a separate order, but are merely a conglomeration of hypho- 

 mycetes and bacteria. Zederbauer had not seen any of the rnyxo- 

 bacteria, and his criticisms are easily disposed of. Thaxter has not any- 

 thing new to add to the general characteristics of the group as a whole, 

 but he chronicles a number of new species belonging to the genera 

 Chondromyces, Myxococcm and Polyangium, all of them of a reddish- 

 yellow colour. He thinks that probably the myxobacteria represent 

 transitional conditions between the higher bacteria and the lower 

 mycetozoa. 



American Fungi. — A. P. MorganJ traces the changes of nomen- 

 clature in the fungus originally called Tiibercularia fasciculate/, by lode, 

 a discomycete growing on Carpinus. He finally names it Dermatdla 

 scolinus. Six new species of Pyrenomycetes are described by the same 

 author.§ They are saprophytic on wood. 



J. B. Ellis and B. M. Everhart || describe a number of new American 

 species, both Deuteromycetes and Pyrenomycetes. Elias J. DurandlT 

 publishes diagnoses of three species of Discomycetes. A new Hypho- 

 loma collected in New Mexico is described by T. D. A. Cockerell,** and 

 W. A. Kellerman ft describes a new Ncemosphara found on old stems of 

 Luctuca virosa, and a new Peronospora %% which had dwarfed its host 

 plant Floerlcia proserpinacoides. The whole plant was invaded by the 

 fungus. The same writer §§ gives a second and third instalment of his 



* Comptes Rendus, exxxix. (1904) pp. 83-5. 



t Bot. Gazette, xxxvii. (1904) pp. 405-16 (2 pis.). 



X Journ. Mycol., x. (1904) pp. 98-9. § Tom. cit., pp. 161-2. 



|| Tom. cit., pp. 167-70. ' i Tom. cit, pp. 99-100. 



** Tom. cit., p. 108. tt Tom. cit., pp. 113-4 (1 fig.). 



» Tom. cit., pp. 171-2 (1 pi.). §§ Tom. cit., pp. 144-9, 174-82. 



