565 
1908-9.] The Pathogenesis of Micrococcus melitensis. 
its milk seven weeks after infection, another three months after infection. 
A third showed no signs of the coccus up to four months after inoculation, 
when it ran “ dry ” ; six months later still — that is, ten months after experi- 
mental inoculation — this goat dropped two kids, and three days later the 
coccus was first detected in the milk. 
A series of daily observations during the summer of 1906 showed that 
although the excretion of M. melitensis in the milk during some stages of 
the infection of the milch goat is persistent, it is by no means constant or 
even consistent ; nor was it possible to detect any correlation between the 
atmospheric temperature curve and the number of cocci excreted in the 
milk. 
So that for the moment the only explanation that can be offered of the 
day-to-day variations in the number of cocci present in the milk is that the 
micro-organism, lodged in a suitable soil and richly supplied with a medium 
of high nutritive value, multiplies rapidly in the interstices between and 
upon the surface of the gland-epithelium cells. This multiplication proceeds 
up to a certain point, when, owing perhaps to the mechanical irritation set 
up by the mere presence of the coccus, a flushing process is carried out by 
the milk itself, which removes the excess of cocci and leaves behind in the 
gland tissue only those cocci which are in intimate relationship with the 
gland cells. A certain interval is then necessary for further multiplication 
of those cocci left behind, when the process is repeated again and again. 
PRIMATES. 
Monkey, Man. 
Both the Rhesus and Bonnet monkeys resemble man in that they 
are susceptible to all the methods of experimental inoculation already 
enumerated, and in addition to infection through apparently intact mucous 
membranes. In these animals, as in man, the infection is usually of the 
subacute or chronic type, though occasionally acute infections of a rapidly 
fatal course are observed. In fact, the introduction of living cultures into 
the tissues of the monkey, or the administration of infective food, is 
followed by an attack of fever strictly comparable in general symptomat- 
ology, and in the course of the temperature curve, to one or other of the 
various types of the disease clinically distinguished in man. The multi- 
plication of the organism in the peripheral circulation and the production 
of specific agglutinins in the serum are similarly demonstrable, although 
the disease usually runs a shorter course, and in the majority of the experi- 
mental infections would end in complete recovery. 
