154 BETTS : THE FUNGI OF THE BEE-HIVE. 
manner; they exhibit strong positive heliotropism. The ee 
is spherical, greenish-grey when mature, 70-190 » in diameter. e 
sporangium-wall is semi-transparent, smooth, and very fugitive when 
mature; it usually deliquesces if it so much as touches a neighbour- 
ing hypha. The columella is spherical to oblong, or sometimes 
slightly pear-shaped, 55-22 x 50-20 m, the longer diameter being the 
vertical one (Fig. 20). There is a basal collar. The spores vary in 
Fig. 21.—AMucor erectus, Spores. x 1,400, 
TARR A 
wn 
Iss W/ 
We Wy SN 
AL NY ; 
Fig. 22.—Mucor erectus. Zygospore. x 640. 
size and shape (Fig. 21), 11-7 x 6-3 pm (average 7 x 5 m3; some are 
almost spherical, 2-3 in diameter). In the mass they are grey in 
colour. 
The zygospores and azygospores were produced in cultures on 
potato and on bread, but on no other media. They are ornamented 
with star-like thickenings of a darker red-brown than the rest of the 
surface (Fig. 22). Good specimens of zygospores are go p in 
