260 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



strains from culture H, aud in no case did a growth fail to show zygo- 

 spores at the line of contact. Tlie constant presence, in all these cultures 

 which have been found spontaneously producing zygospores, of two 

 opposite strains, the individual character of each of which is the same 



TABLE IX. CcLTUKE H. 

 (Zygospore material obtained from Prof. F. L. Stevens, Raleigli, N. C.) 



Transfers obtained from germinations of 

 single suspensors. 



Transfers 11,8 and IIj,, were obtained from sporan- 

 gia; IIi5 to Hi-; came from germinations of single 

 suspensors ; HX,;, IIY,,, and IIZi, were from the 

 suspensors of a single zygospore. 



Contrasts. Results. 



March 12. March 16. 



Transfers obtained from sporangia from a 

 culture producing zygospores. 



Hg to Hi3 = !{, = A(-) 



Strain EquiTalents. 



A(-) A(+) 



F(-) F{+) 



Hi 

 H2 

 H3 

 H4 



Hs 



He 



Hr 



Hs 



H9 



Hio 



Hii 



Hi2 



His 



His 

 H16 

 HYn 

 HZ17 



His 



Hi9 



HX, 



(Hi4 mixed) 



