1897] ZYGOMYCETES, SYNCEPHALASTRUM AND SYNCEPHALIS 9 
development of its sporangial hypha recalls that of Dimargaris, 
from the fact that the portion corresponding to the terminal 
spore appears to bud, as it were, from that corresponding to the 
basal spore after the latter has become almost fully formed and 
has assumed its more or less characteristic shape (jigs. 23, 24, 
27528). 
Syncephalis Wynnee and S. pycnosperma possess a further 
interest from a structural standpoint, in that they illustrate an 
extreme development of the type hitherto represented only by 
S. fusiger. Bainier, in his description of the latter species, dis- 
tinguishes it as the type of a new genus which he calls Micro- 
cephalis, for the reason that the sporangial filaments arise in 
pairs from a common basal piece, corresponding to the basal 
spore or spores which bear similar relation to the erect spore- 
rows in species like S. cordata or S. nodosa. In S. fusiger this 
piece, instead of becoming converted into one or more spores, 
remains sterile and constitutes a specially developed organ, or 
secondary sporophore, which this author compares to the sepa- 
rable sterile piece on which the spore-rows are inserted in the 
species of Piptocephalis, although in the last instance this piece 
would seem to be more properly comparable with the swollen 
extremity of the fertile hypha in Syncephalis. So marked a 
differentiation of this secondary sporophore as is found in S. 
Wynnee might seem to call for generic recognition were it not 
for such connecting links between this and the ordinary forms 
as are furnished by S. pycnosperma and S. fusiger, in view of which 
the character can hardly be considered of more than sub-generic 
value. : 
The zygospores of species of Syncephalis were first discov- 
ered by Van Tieghem in the common S. cornu, but, as far as the 
writer isaware, have been observed in only one other instance, 
those of S. xodosa having been described and figured by Bainier 
in his well-known “Etude sur les Mucorinées.” The last men- 
tioned species is very common in this country, and one seldom 
fails to obtain its zygospores in abundance whenever it grows on 
a copious substratum of other mucors. From the peculiarities 
