BLAKESLEE. — SEXUAL REPRODUCTION IN THE MUCORINEAE. 227 



cells, and uo mention is made of any inconstancy in the formation of 

 zygospores under like culture conditions. Altliough no morphological 

 description nor figures are given of these forms to which Hansen has 

 given noinina nuda, their action in cultures and the fiict that they were 

 obtained from the soil which we know is a source of homothallic Mucors, 

 renders a homothallic condition probable. 



Mucor flavus Bainier. 



This species was found by Bainier ('03, p. 157-9) on decomposing 

 agarics and generally with zygospores. " Upon whatever substance one 

 cultivates tliis form one easily obtains, towards the end of fall, a large 

 number of zygospores."' They were thus obtained on bread, horse dung, 

 agarics, flaxseed flour, and in cell cultures on decoction of horse dung 

 and of prunes. " "When the plant decides to give zygospores they are 

 produced in great abundance." They form on sporangial filaments, as in 

 M. racemosus, and as many as four may be seen one above the other in 

 scalariform fashion. 



Mucor communis Bainier. Mucor prolificus Bainier. 

 Mucor lim.pidus Bainier. Mucor vulgarus Bainier. 



In these four unfigured species of Bainier (*03) the zygospores are 

 formed in a scalariform fashion on sporangiophores. Zygospores were 

 found during summer in alcoholic prune juice in cell cultures which had 

 been kept in a cool place. 



Mucor neglectus Bainier (not Vuilleniin, nor Hansen). 

 Mucor vicinus Bainier. 



In these two foraus azygospores only formed under the conditions 

 given by Bainier (03) in the species mentioned above. 



Zygorhynchus heterogamus Vuillimin ('03'). 

 MucoK HETEUOGAMLS Vuillemin ('86'). 



This species was found by Vuillemin ('87) on a spontaneous bread 

 culture. The unequal gametes are cut off from branches of the same 

 erect filament from which also sporangia may develop. 



Zygorhynchus Moelleri Vuillemin. 



This species was found by A. Moller ('03) from cultures of the 

 mycorrhiza of pine and oak. In 18<S4 this species came up iu the 



