234 PROCEEDINGS OF THE AMERICAN ACADEMY. 



After the running out of the original Harvard strain, isolated cases of 

 zygospores were occasionally found in cultures of starchy material in the 

 laboratory, and cultures on paste of the shells of almond nuts have 

 always produced them in abundance. 



The species is heterothallic. 



Rhizopus necans Massee. 



This form is described by Massee ('97) as causing disease of lily bulbs 

 brought from Japan. " Several large spiny zygospores were found in 

 the matted mycelium present in bulbs in the last stage of decay, and pre- 

 sumably belong to our fungus." The single zygospore figured shows no 

 mycelium connections except the halves of the suspensors nearest the 

 zygospore. 



Rhizopus Artocarpi Raciborski. 



Raciborski ('00) found this species in Java infecting the male inflores- 

 cence of breadfruit {ArtncarpKS inclsa). The zygospores did not occur 

 on the host plant, but appeared on an agar culture a week old which was 

 contaminated wilh a Hyphoraycete. No figures are given, and it is not 

 impossible that in the laboratory cultuue where zygospores appeared, 

 their formation was due to an accidental infection with a complemen- 

 tary strain. 



Absidia capillata van Tieghem. 



The zygospores of this species of van Tieghem were found in the in- 

 terior of the horse dung and on the lower face of the substratum in con- 

 tact with the bottom of the plate containing it. The description and 

 figures (Figures 32 and 35) represent zygophores originating from the 

 same branch in close proximity to the future zygospore, and there is no 

 mention of cultures in which zygospores were Jiot found. Sucli a con- 

 dition would force us to consider the species homothallic. 



Absidia septata van Tieghem. 



Cornu found zygospores of this form which van Tieghem ('77, p. 360) 

 refers to A. septata^ on the lower side of a cork hermetically sealing 

 a flask in which grapevine roots were preserved. " In both cases 

 (-4. capillata and A. septata),^' says van Tieghem, " zygospores were 

 produced in an atmosphere poor in oxygen when the vegetation had 

 become sufficiently checked and the formation of sporangiophores com- 

 pletely suppressed by this poverty of oxygen," The description of 

 A. capillata as regards the origin of the zygophores is made to apply 



