24 The Philippine Journal of Science ms 
It was noted that fresh dung which had not been allowed to dry 
out to some extent, before being placed in covered dishes, never 
produced any mucors even when inoculated with the spores or 
hyphae. Moreover, when unsterilized dung, even after being 
slightly dried, was mashed, mixed, and placed in an Erlenmeyer 
flask the growth of molds which appeared on it was always 
very scanty. This also appeared to be due to an excess of mois- 
ture, for a slight drying does not greatly affect more than the 
superficial layers and the mixing of the mashed dung causes a 
redistribution of the moisture. It would appear, however, that 
the presence of the moisture is in itself not the cause of the 
detrimental effects observed, for a vigorous growth of molds was 
always produced on sterilized dung, and while it was found that 
sterilizing in an autoclave produced only slight changes in the 
amount of moisture it did increase it. The probability is that 
the excessive amount of moisture favored the growth of other 
organisms which were detrimental to the growth of the mucors. 
This point will be discussed later. It is to be noted further that 
sterilized dung, even when fairly dry, produced a luxuriant 
growth of mucors and that they persisted on it until the dung 
was apparently thoroughly air dry, while they always disap- 
peared from the unsterilized dung in less than ten days and while 
it was still quite moist. 
The experiments already mentioned having apparently elimi- 
nated the possibility of the mucors causing their own death in 
the original cultures by either excreting toxins or using up all 
of the available food supply, it became advisable to test the effect 
of the growth of the other fungi on both of the molds. This was 
done on dung in Erlenmeyer flasks. This method proved to be 
particularly convenient as infections could easily be prevented, 
and so it was used almost exclusively in subsequent experiments' 
Fresh dung was collected, dried slightly, then mashed and thor- 
oughly mixed, and a layer about 2 cm deep placed in the bottoms 
of the flasks. The mouths of the flasks were then plugged with 
absorbent cotton. Two of the flasks were kept as checks and 
the others sterilized by heating in an autoclave for fifteen min- 
utes at 120° under a pressure of one kilo. This same method 
was always followed when Erlenmeyer flasks were employed 
In order to test the effect of the growth of the fungi on Ah- 
fdmcaerulea fourteen 600 cc flasks were prepared as above on 
the thirteenth of March. Two were kept as checks and twelve 
sterilized The latter were inoculated in duplicate on March 
18th, as follows: 1, Absidia caemlea; 2, A, caerulea and Mucor 
