ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 495 



subject, and the present writer confirms the results of that author in 

 the main. Experiments were made on Conferveae, the spores of which 

 were made to germinate in Knop's nutritive solution. The pyrenoids 

 are composed of nuclear substance, which is probably supplied to the 

 chromatophores for the purpose of starch formation. Filamentous 

 processes connecting the pyrenoids with all parts of the chromatophores 

 were observed, and the impression was given of an organically connected 

 system of pyrenoids serving physiologically for purposes of nutrition, 

 having as its centre the cell-nucleus. Further information is promised 

 in a later paper. 



Fungi. 



(By A. Loehain Smith, F.L.S.) 



Pseudo-Absidia vulgaris.* — Notes are published by A. Sartory 

 on the biological properties of this filamentous fungus. It grows in 

 summer on somewhat dry horse-dung, but it is easily cultivated on 

 carrot, etc., growing most luxuriantly at a temperature of :»4-35° C. 

 Higher temperatures are hurtful or fatal. Yeast-cells are formed in 

 agitation of the culture medium. It is not pathogenic. 



Notes on Mucors.f — A. F. Blakeslee writes a series of notes for 

 students, summing up the work done on Mucorini within the last few 

 years. He examines the work and results obtained by Hagen, who 

 isolated species from the air, and by Lendner, who has worked at the 

 Mucorini of Switzerland. The cytology of the group has been studied 

 by Gruber in Sporodinia and by Dangeard in Mucor fragilis. Wis- 

 niewski has followed the course of zygospore formation in Zygorhynchm 

 Moett&ri, and Dauphin has made a study of the MortlerelJse. Blakeslee 

 gives notes and criticisms of the results published by these writers. 



Sexual Reproduction in Endomyces Magnusii.J— A. Guilliermond 

 has cultivated this fungus, and describes the formation of the fruits. 

 Ludwig, who discovered -the fungus, and later, Brefeld and Dangeard, 

 had noted anastomosis in the mycelium, but the formation of asci had 

 not been followed. Cultures were made on carrot by Guilliermond, who 

 was able to watch the complete growth and development. At the ends 

 of the hyphge were formed either a cell with dense contents, the future 

 oogonium, or one slighter in size and with hyaline contents, the anthe- 

 ridial cell. The oogonial cell contains one or more nuclei and bends 

 over ; in many cases it becomes an ascus without any conjugation, a 

 transverse division separating the more dense upper portion from the 

 lower part of the cell which is cut off to form the pedicel. More 

 frequently conjugation takes place with an antheridial branch at an 

 early stage before complete differentiation of either cell has taken place. 

 The tip of the antheridial branch is cut off by a transverse wall, fusion 

 takes place with the oogonial cell, their contents and nuclei pass over, 

 and the two nuclei fuse. The fused nucleus increases in size, and 



* C.R. Soc. Biol. Paris, lxvi. (1009) pp. 705-6. 



t Bot. Gaz., xlvii. (1909) pp. 418-23. 



% Cornptes Rendus, cxlviii. (1909) pp. 941-3. 



