Mould Growths upon Cold-store Meat. 119 
first. In nature each conidiophore usually bears a few large 
spores, but under culture conditions these large spores bud 
forth, giving rise to chains of smaller spores, the so-called 
Hormodendron stage. The youngest conidium is that at the 
distal end of the chain, the large conidia next the conidiophore 
being the oldest. Each conidium of a chain arises as a small 
bud on that immediately behind (cf. Fig. 2). 
(1) toa.m. Mon. (2) 3.0p.m. Mon. (3) 6p.m. Mon. (4) 9.0a.m. Tues. 
Fig. 2. Formation of conidia of Cladosporium herbarum. 
(Hanging drop culture). x 900. 
While still quite small, this bud is cut off by a membrane 
from the parent conidium, and continues to enlarge. The mem- 
brane between the young conidium and its parent is thickened 
from both sides simultaneously with the growth of the former, 
until finally, under certain conditions of microscope illumination, 
it appears as a small intercalary piece (cf. Fig. 3). On separation 
of the conidia, these “‘intercalary pieces”’ break asunder, along 
the line of the original membrane between the two conidia. Thus 
the majority of the conidia when separated, show a small stalk 
at each end, giving them a somewhat lemon-shaped appearance. 
Fig. 3. Conidia of C. herbarum showing thickened end walls. x 3100. 
The method of spore formation is the same in all the present 
series of forms. : 
