388 Miscellaneous. 



Towards the end of the summer the empty zoosporaiigia separated 

 from the mycelium often encumber preparations ; generally they 

 present, at various parts of their wall, especially at the extremities, 

 swellings formed by a layer of undifferentiated refractive proto- 

 plasm. 



During the autumn months, in the Molgulce produced in the spring, 

 the mycelium presents a great quantity of zygospores. These 

 reproductive bodies, which are much larger than the zoospores, 

 originate isolatedly, but at very closely approximated points, where 

 several (usually four or five) filaments of the mycelium conjugate. 

 The zygospores have a finely granulated envelope, perhaps even 

 slightly echinulate. During the winter, at the beginning of Feb- 

 ruary, these zygospores germinate by emitting two equal filaments, 

 terminating in points and slightly divergent, which give the spore 

 in course of evolution the form of a pair of compasses. The two 

 branches of these compasses open more and more, and the compass- 

 stage gradually becomes converted into a fusiform stage, in which 

 the spore is no longer visible except as a median swelling, which 

 soon disappears completely. 



(Side by side with these various forms we find all the year round 

 pretty long tubes, wider than the mycelium from which they sepa- 

 rate readily, and rounded at the two extremities. Upon their walls 

 these tubes present a fine plasmatic deposit arranged in two inter- 

 crossing spirals, or perhaps disseminated around vacuoles placed 

 end to end throughout the length of the tube. The meaning of 

 these pai'ts completely escapes me. 



Anurella roscovifana, Lac.-Duth., contains a Nephromyces (N. 

 roscovitanus) nearly alhed to N. Molgularum, but nevertheless quite 

 distinct. 



The species parasitic upon Litlioneplirya eugyranda, and which I 

 name Nephromyces SoroHni, is very distinctly characterized by the 

 form of its regularly pyriform zoosporangia with two refractive 

 masses, one at the apex, the other at the base, at the point where 

 the sporangium is inserted upon the mycelium. In the Lithonephryce 

 the kidney is almost entirely filled by a single very voluminous con- 

 cretion. A very limited space is left, therefore, for the symbiotic 

 fungus, and hence the latter is much less abundant than its con- 

 geners parasitic upon the Molguhe. 



The arrangements of the laboratory at Wimereux have not per- 

 mitted me hitherto to make experiments upon the culture of the 

 Fungi of the genus Nephromyces in artificial media containing 

 guanine or iiric acid. I think, however, that such cultures may be 

 possible, and that these Fungi are useful to the Tunicatcs which 

 they infest by freeing them of the excreted products, which, with- 

 out them, would rapidly choke up the kidney, which is destitute of 

 any evacuatory duct.— Comptes Rendus, April 16, 1888, p. 1180. 



