BLAKESLEE. — SEXUAL REPRODUCTION IN THE MUCORINEAE. 225 



Mucor spinosus van Tiegliem. 



Baiiiier ("84, p. 204) obtained the zygospores on alcoholic decoction of 

 pears and plums during the month of August. They are not produced, 

 he says, during the winter. The zygospores are figured (Plate VII, 

 Figure 6), forming in a scalariform fashion between two filaments, one 

 of which bears terminally a columella. 



Mucor circinelloides van Tiegliem. 



Bainier ('84) found zygospores of this species forming in the moist 

 lower portion of a horse dung culture which had probably been sterilized 

 according to Bainier's method with carbon bisulphide. They do not form 

 in decoction of malt nor of prune. The single zygospore figured fails 

 to show the hyphal connections. 



Mucor erectus Bainier. 



According to Bainier ('84), cultures in prune juice in winter and spring 

 constantly give very numerous zygospores. Double azygospores are as 

 abundant as zygospores. One of the zygospores is figured (Plate VIII, 

 Figure G), formed from the base of a sporangiophore. 



Schroter ('86'', p. 204) reports that the zygospores of this species were 

 found by Eidam, and Fischer ('92, p. 197) has apparently also observed 

 them. 



Mucor fragilis Bainier. 



Bainier ('84) states that the zygospores of this species are obtained with 

 greatest ease during the winter and spring in decoction of prunes, and 

 that the culture becomes literally black with them at the end of eight 

 days. 



Vuillemin ('04'') has used the zygospores of this species in his investi- 

 gation of the zygosporic membranes. 



Mucor mollis Bainier. 



Although the zygospores of this species are described and figured by 

 Bainier ('84), their method of formation is not determinable. 



Mucor tristis Bainier. 

 Mucor modestus Bainier. 



Bainier ('84) mentions obtaining zygospores of these two species, but 

 descriptions and figures are lacking in both cases. 



VOL. XL. — 15 



