138 Transactions British Mycological Society. 
upon bacon also. When young, the colonies are white in colour, 
but when mature they are bluish green. The isolations proved 
generally to be P. expansum, but one has been provisionally 
identified by Dr Thom of Washington as P. asperulum Bainier. 
Some evidence has been obtained that certain isolations of 
P. expansum from cold-store meat will germinate and grow at 
— 6°C., but development is very slow and after more than two 
years the colonies in the culture tubes or on meat are little- 
more than just visible to the naked eye. Growth at this low 
temperature is sometimes more marked if germination of the 
spores has proceeded for 24-48 hours before the culture tubes 
are placed in the cold store. At — 1° to — 0°5°C.. growth is 
more vigorous and at 2° C. it is active. 
The spores and young mycelial growths also of this fungus are 
able to withstand exposure to a temperature of — 6° C. for long 
periods. Growth has sometimes taken place or has been resumed 
after 2} years at this temperature. 
The large colonies of Penicillium seen on contaminated meat 
are in marked contrast to the small growths which have 
been produced under experimental cold storage conditions, 
and point to the fact that at some time or other the tem- 
perature of the meat has risen to about or just above freezing 
point. Spores of Penicillium are always present in the air, and 
doubtless are deposited upon the surface of the meat, ready to 
develop if conditions are suitable for growth. These bluish- 
green moulds are entirely superficial. 
VII. SACCHAROMYCES spp. 
Both white and pink yeasts were of common occurrence on 
meat contaminated with mould fungi. These forms develop 
with great rapidity at temperatures just above freezing point, 
but there is no evidence yet that they will grow below zero. 
The fungus described some years ago by Klein (10) as the cause 
of brown spots on chilled beef should, perhaps, be placed here. 
Yeast colonies in a dry condition are often brownish in colour, 
but it is not possible to be certain of the identity of the organism 
which Klein described. The white and pink yeasts isolated from 
meat do not form spores, and hence belong to the genus Torula 
used in the sense of Hansen and Jorgensen. 
VIII. THAMNIDIUM spp. 
Species of Thamnidium were frequently isolated from meat — 
of various kinds in cold stores, which had become cohtaminated 
by mould growths, the type of which known in the meat trade 
as “‘whiskers’”’ being usually due to species of this genus. Upon 
