22-4 PROCEEDINGS OF THE AMERICAN ACADEMY. 



4; '83^ Plate XVII, Figure 6; Plate XVIII, Figure 9; '84, Plate 

 VIII, Figure 1). 



Leger ('96, p. 60) also encountered these zygospores in his researches, 

 but never obtained a sulHcieut number for study, although he followed 

 Bainier's method during the months said by him to be most favorable for 

 the purpose. 



Saito ('04) mentions this species as common on plate cultures exposed 

 to the air. No description is given, but in the three zygospores figured 

 (Plate II, Figure 7) zygophores are represented as belonging to separate 

 hyphae. 



Syzygites ampelinus Hildebraiul. 

 Mlcor racemosus sec. Fischer. 



From a sowing of his Miicor Vitis on black bread Hildebrand ('67) 

 obtained zygospores below the sporangial growth. " The origin of the 

 conjugating branches differs from that in Sporodinia, since they never 

 arise in close proximity from the same hypha. They belong without 

 exception to different branch systems." 



Fischer ('92) places this form under M. racemosus, together with 

 Mucor Vitis, with which it is probably connected. 



Mucor racemosus, var. brunnea Morini. 



According to Morini ('96) the zygospores of this form may be obtained 

 by allowing the nutrient to become gradually exhausted, or by inducing 

 a gradual desiccation of the substratum, though not infrequently zygo- 

 spores are formed on a substratum rich in nutriment. In all cases the 

 sexual phase supposes full vitality on the part of the fungus, hence the 

 substratum should be conveniently arranged, and in sutHcient quantity, 

 so that the mycelium may spread freely. In a suitable temperature, 

 principally from January to April, zygospores form in horse dung, moist 

 bread, and solution of peptone. In horse dung they are most abundant, 

 and form after about ten days. In peptone solution the production of 

 sporangia is abundant, while that of zygospores is scarce. The want of 

 a fre(|uent renewal of air seemed to lander the development of zygospores, 

 though it favored oidium formation. 



Mucor tenuis Bainier. 



In this species, described by Bainier ('83^ p- 353), no zygospores 

 were found, but in decoction of plums during December, January, 

 Febi'uary, and March, azygospores were produced on erect filaments. 



