40 
globules, forming a plentiful supply of cream. There was 
no appearance of dotted matter or any fungoid growth when 
examined by powers varying from 200 to 1500. The small- 
est oil globules exhibited (as usual) great molecular activity. 
A bottle was filled with some of this milk and securely 
corked, other portions of the milk were placed in open cups, 
one cup was kept in a cabinet which was closed during the 
day, the milk of the second cup was placed in a closet the 
atmosphere of which I knew to be favourable to the growth 
of fungi, the Mucor Mucedo being the most abundant and of 
the same family as that mentioned as having been found in 
cream by M. V. Essling. The milk in the bottle and that 
in the cups was examined daily, precautions being taken to 
close the bottle speedily after a portion was removed. On 
the third day the milk in the open cups was sour to the 
smell, but no change appeared visible under the microscope ; 
the upper portion of the milk in the bottle had become very 
rich in oil globules by the formation of cream. On the 
fourth day the casein had coagulated in the milk in the 
open cups, and the flaky precipitate was visible under the 
microscope ; the pellicle surrounding the oil globules now 
appeared to be very easily ruptured, and with the slightest 
pressure some of the globules could be joined together— 
sometimes a number of globules which had been ranged in 
line by a current would coalesce by a slight movement of 
the fluid, and form an elongated mass. Fifth day, no appre- 
ciable alteration. Sixth day, the milk which had been 
placed in the closet had patches of mould visible on its 
surface; a microscopical examination of this mould showed 
it to be the Mucor Mucedo, such as I had frequently found 
on fruit which had been left in this closet. The fungi 
appeared on the surface only, no trace of it could be found 
in the milk taken from various depths. The milk in the 
cup kept in the cabinet exhibited no appearance of the 
Mucor Mucedo or any other vegetable or animal organism ; 
