ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 333 



New Chytridiaceae.* — Serbinow describes Sporophlyctis rostrata, a 

 new genus and species which grows on the algae Draparnaldia and Chato- 

 phora. There is a bladder-like cell provided with a small beak and with 

 a root-like filament, which is often branched. A sporangium is formed 

 later, inside which the spores germinate and pierce the sporangium- wall. 

 Sexual reproduction takes place by the fusion of two individuals, the 

 oospore is surrounded by a spinous membrane. 



Rhabdium acutum^ also a new member of the Chytridiaceae, was 

 found by P. A. Dangeard parasitic on filaments of Spirogyra and 

 (Edogo ilium. It consists of a short slender tube which projects from 

 the surface of the alga. A disc at or near the base acts as a sucker. 

 The whole plant transforms itself into a zoosporangium, the zoospores 

 numbering about 1G. They escape slowly from the extremity of the 

 tube, remain active for a time, then settle down on the host and put out 

 a filament which penetrates the cell-wall, the external part elongates 

 into the tube which in time becomes the sporangium. The writer gave 

 the name Rhabdium on account of the rod-like appearance of the mature 

 fungus. 



Disease of Chestnut Trees 4 — L- Mangin contributes a note as to 

 the cause of a disease that has worked great havoc in the forests of 

 southern France. It is caused by a fungus with extremely fine mycelium 

 that lives as a parasite on the mycorhiza of the tree and gradually 

 destroys the roots up to the base of the trunk. Usually the hyphre of 

 the parasite are confined to the mycorhiza or to the tissue of the root, it 

 is rarely found free in the soil, but occasionally it attacks rhizomorphal 

 strands not connected with the chestnut, and it is only on these 

 rhizomorphs that the fructification has been found. The mature form 

 of fructification resembles the oospores of a Peronospora, and for this 

 reason the fungus has been classified along with the Oospore* as 

 Mycelophagus Castanece. A further and more detailed communication 

 in regard to the disease is promised. 



Mucorini.§ — L. Matruchot gives a much longer and more detailed 

 account of Cunni/ighamella africana, than has hitherto been published. 

 It has morphologically the form of an (Edocephalum, but Matruchot 

 places it among the Mucorini because it serves as host to Piptocephalis, 

 a parasite only on Mucor or Piloiolus. 



C. Wehmer || describes a new species Mucor hiemalis, the sporangio- 

 phores are usually unbranched, the sporangia small and dark ; zygospores 

 were not seen. It grows on hemp. 



Study of Absidia.1" — Paul Vuillemin passes in review the various 

 known forms of Absidia. The genus Js characterised by the regular 

 growth of the stolons which form arches at the summits of which the 

 sporangiophore rises. Absidia repens deviates from the type in , the 



* Eeprint from the K. St. Petersburg. Naturforscherges., xxx. See also Cen- 

 tralbl. Bakt., x. (1903) pp. 102-3. 



t Comptes Eendus, cxxxvi. (1903) pp. 473-4. See also Ann. Myc., i. (1903) 

 pp. 61-4 (I pi.). % Comptes Ren Jus, cxxxvi. (1903) pp. 470-3. 



§ Ann. Myc, i. (1903) pp. 45-60 (1 pi.). 



|| Tom. cit., pp. 37-41 (7 figs.) 



\ Comptes Eendus, cxxxvi. (1903) pp. 514-6. 



June 17th, 1903 z 



