242 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Syzygites echinocarpus Hildebrand. 



This form was found by Hildebrand ('67) on an open moist black 

 bread culture of Arthrobotrys and another mucor. The zygophoric 

 branches arise either both from a lateral branch which dichotomizes near 

 its origin, forming two branchlets which bend toward each other to con- 

 jugate ; or secondly, the two zygophoric branches arise close together 

 directly from a hypha ; or thirdly, they arise from different threads of 

 the mycelium. The first and the third conditions seldom occur. Of 

 twelve figures of zygospores, five show an undoubted homothallic con- 

 dition. Hildebrand has here and in his S. ampelinus made a special 

 study of the origin of the zygophoric branches, and if his account is cor- 

 rect the species is homothallic. 



De Bary ('84, p. 1 63) thinks this may belong to Chaetocladium, and 

 A. Fischer ('92, p. 287) places it under Chaetocladium Brefeldii. The 

 figures of these zygospores, however, differ from those of Brefeld, and the 

 thallic condition which is here described has been determined in neither 

 C. Brefeldii nor C. Jonesii. It would seem unwise, therefore, to connect 

 this form with any known species in the absence of further information 

 concerning it. 



Piptocephalis Freseniana de Bary. 



The zygospores were discovered by Brefeld ('72) while investigating 

 the parasitic relations of this plant. He does not state whether they 

 were first found in slide or in gross cultures. " It is highly probable that 

 the parasite was incited to sexual reproduction through the_ especially 

 luxuriant and undisturbed nourishment on the host. The moi'e abun- 

 dantly it occurred the more in the background did the nonsexual form 

 remain, and this was especially the case if the development received a 

 normal and not too strong impulse through a moderate temperature." 

 Brefeld figures (Plate VI, Figure 19 i) a single spore giving rise to an 

 intricate mycelium which bears both zygospores and conidiophores. The 

 zygophores of one of his zygospores, moreover, can be distinctly traced to 

 the same branch. If this is a correct representation, therefore, the 

 zygospores in Piptocephalis Freseniana originate from branches of the 

 same mycelium. Since the importance of this point was not recognized 

 at the time, we can hardly expect in all of Brefeld's elaborate drawings 

 an absolute accuracy as to the finest ramifications, especially in view of 

 the fact that he himself tells us that the condition was much more 

 complex than represented and that in general the mycelial hyphae are 



