236 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Absidia scabra Cocconi. 



This form was found on horse dung by Cocconi ('00). When the 

 nutriment in the dung becomes impoverished by the asexual generations, 

 the sexual generation occurs. In the formation of a zygospore " two 

 superficial branches, each of which belongs to a distinct mycelial-hypha, 

 direct themselves toward each other till they meet." 



Professor Thaxter has found zygospores of an undescribed species of 

 Absidia on a culture of refuse from a termite's nest from West Africa. 

 In tube cultures made at the time from sporangia, no zygospores de- 

 veloped. In preparations examined of this material the zygophores 

 remain separate as far as they can be followed. 



Mycocladus verticillatus Beauverie. 



This fungus was found by Beauverie ('00) growing in abundance on a 

 damp wall with many other moulds. The zygospores were found in 

 a culture of the sterile form of Bolrytis cinerea where the two species 

 developed together with intrication of their filaments. The culture was 

 five months old, and the zygospores were extremely numerous. Beau- 

 verie suggests that their abundance may have been because of the sup- 

 port which filaments of the Botrytis furnished. Nothing is said of the 

 character of the substratum except that it had become exhausted by a 

 luxuriant vegetation and had almost completely dried. The single figure 

 of a zygospore has the suspensors incompletely drawn. In the meagre 

 description given us, we have little clue to the thallic condition, except 

 the fact that the zygospores were obtained apparently in but this single 

 culture, although the fungus was subjected to varying conditions in 

 Beauverie's physiological investigations. If this zygosporic culture were 

 the first culture made — a not improbable supposition from its age an<l 

 admixture with Botrytis — it can easily be seen, upon an assumption 

 of a heterothallic condition, why zygospores should occur here and not 

 later. 



Thamnidium elegans Link. 

 During May and June Bainier ('84) obtained the zygospores of this 

 well-known species in pure cultures in great abundance. They are 

 borne upon erect filaments, which also produce the dichotomies, and a 

 scalariform series is figured (Plate X, Figure 7) between two separate 

 hyphae which are each terminated by a columella. 



