116 Transactions British Mycological Society. 
which occur upon meat and upon vegetable substrata, and the 
observations upon the differences between these closely related 
strains are recorded here. 
Several of these fungi are of common occurrence as moulds 
upon different kinds of organic matter, e.g. Cladosporium her- 
barum, but three are apparently new to science. Some occur 
commonly as moulds upon vegetable debris within and in the 
vicinity of abattoirs, and it is likely that all so occur. The 
similarity of the types of mould occurring on meat imported 
from different countries is very striking, and point to the cosmo- 
politan distribution of these fungi. 
II. CLADOSPORIUM HERBARUM. 
This fungus has been shown to be the cause of the trouble 
known in the frozen meat trade as ‘‘Black Spot.” Several 
strains isolated from different kinds of meat have been proved 
to possess the power of growth below freezing point. Strains 
of this fungus have also been isolated from other sources, chiefly 
vegetable substrata, and some of these are also able to grow 
at — 6°C. For comparison, cultures of various species of 
Cladosporium were obtained from the Centraalbureau voor 
Schimmelcultures, Amsterdam. These were: 
C. herbarum (No. 43) C. epiphyllum_ (No. 44) 
C. Aphidis (No. 42) C. carpophilum (No. 47), 
also C. butryi and C. cucumerinum, neither of which could be 
induced to fructify. In this connection it is noteworthy that 
other forms occasionally degenerated in the course of the work 
when cultivated for several generations on meat extract-peptone- 
agar. 
In a paper on the mould-growths of frozen meat, Monvoisin (13) 
makes no special mention of Cladosporium. Bidault (2) records 
both Cladosporium herbarum and Hormodendron cladosporioides 
on frozen meat, but, for reasons which will be given later, we 
consider these to be identical. 
In connection with the identification of the fungus causing 
“Black Spot” of meat, it was necessary to examine critically 
many closely related forms of Cladosporium. One of the results 
of this investigation has been to show that many so-called 
species of Cladosporium are not really specifically distinct from 
C. herbarum, but are only slightly different strains of the same 
fungus. 
It is not only on meat that Cladosporium herbarum causes 
black spots. In September 1921, one of the writers saw dead 
fronds of the seaweed Laminaria digitata covered with black 
spots which to the naked eye appeared indistinguishable from 
