563 
1908-9.] The Pathogenesis of Micrococcus melitensis. 
a manner as to remove in many places the superficial layer of epithelium as 
well as the hair, but care was taken to avoid drawing blood. Thus the 
shaved area replaced the scratches, abrasions, and small ulcers that are so 
frequently seen on the udder and teats of the milch goat. Next, the hands 
of the operator being protected by a pair of sterilised indiarubber gloves, 
four drops of freshly drawn milk (amounting in total bulk to 0'2 c.c.) 
from a goat known to be excreting M. melitensis were delivered into the 
palm of the right hand from a sterile capillary pipette, and then thoroughly 
rubbed into the shaved area with movements similar to those practised by 
goatherds as a preliminary to milking. The quantity of the milk used was 
so small that the skin surface rapidly dried, and the goat was then isolated 
in a stall, apart from the other animals. Immediately after the experiment 
was concluded, a sample of the milk that had been used was carefully 
plated out (after suitable dilution) and found to contain 24,800 M. melitensis 
per cubic centimetre ; the approximate number of cocci therefore that came 
into contact with the prepared area of skin amounted to 5600. Samples of 
blood were taken from a vein in the ear of this animal, and examined from 
day to day for the presence of specific agglutinins, which first made their 
appearance on the fifteenth day (dilutions 1 in 10 and 1 in 20). Three 
weeks after inoculation the goat was killed and a careful post-mortem 
examination carried out, with the result that the specific organism was 
recovered from the spleen and inguinal glands. 
The post-mortem observations upon animals killed after periods of 
observation varying in duration from three to at least fifty-three weeks are 
extremely interesting as showing that within a very few weeks of infection 
the micrococcus disappears from the general circulation, though still 
present in the spleen to about the end of nine months. Later still, the 
coccus cannot usually be recovered from this organ, but may be found in 
the mesenteric glands and the inguinal glands. In one animal where the 
organism was recovered from the tissues of the mammary glands it could 
not be detected in any other situation in the body ; in another successful 
recovery from the gland substance the coccus was also detected in the 
neighbouring inguinal glands and nowhere else. These results are more 
readily appreciated when arranged in tabular form : — 
[Tables. 
