58 VAN TIEGHEM AND LE MONNIER. 



under the name of 31. Phycomyces} De Bary, who had no 

 better materials for study than those contained in the herba- 

 rium of Kunze, also describes it under Berkeley's name.^ 



The plant is only rarely met with. It does not appear to 

 have been observed in France till recently :— 1st, at Toulouse, 

 by MM. Joly and Clos, on a rag used for wiping a hydraulic 

 machine and impregnated with oil ; it was also found on the 

 parts of the machine itself, on the oil-vessels, and on the 

 flooring of the building; 2nd, by MM. Crouan,^ in a candle 

 manufactory on tallow scum. These authors have, however, 

 added nothing to our knowledge of this curious plant. 



The circumstances under which this species has occurred 

 has supported the opinion that it is exclusively addicted to 

 fatty matters. This will be seen not to be the case, and it 

 is this which explains why M. Carnoy, having met with it 

 at Rome on human excrement and afterwards cultivated it 

 on slices of orange and citron, failed to identify it with the 

 plant of Kunze, and described it as Mucor romanus, a new 

 species.^ We did not make this identification till after we 

 had long cultivated the plant, and had discovered one by one 

 the facts in its history correctly described by Carnoy. 



We first heard of it from a dyer at Wesserling (Alsace) as 

 a large kind of Mucor, which made its appearance in acid 

 cochineal dye. The spores of the specimen sent to us were 

 sown in ordinary cochineal dye, and also in other media, but 

 without any result. We then had recourse to M, Lange-Des- 

 moulins from whom the dye originally came, and the supply 

 which we got from him, when placed under a bell glass in 

 the laboratory, developed, in a few days, a magnificent crop 

 of Phycomyces. It was evident that the dye from his estab- 

 lishment was naturally impregnated with the Phycomyces, 

 since it developed upon it in continuous succession, and it 

 was also evident that success in its cultivation depended upon 

 the freshness of the spores, which rapidly lose their power of 

 germination — a circumstance which explains the feeble power 

 of dissemination possessed by the plant, as well as its rarity. 

 We soon had an additional proof of this. Our first series of 

 cultivations, carried on during several months, were inter- 

 rupted by the vacations. On our return it proved impossible 

 to recommence them. The spores of the old crops had lost 

 by a desiccation of two or three months their power of germi- 

 nation. The plant appeared also to have disappeared from 



1 Berkeley, ' Outliaes,' p. 28 aud 407. 



2 ' Mem. de I'Acad. des Sc. de Toulouse,' 7 Dec. 1865. 



3 ' Floruie du Finislere,' 1867, p. 13. 



< ' Bull, de la Soc. Boy. de Bot. de Belg.,' t. ix, 1870, p. 162, et seq. 



