581 
1908-9.] The Pathogenesis of Micrococcus melitensis. 
coccus has been isolated (by cultural methods) from the second to the three- 
hundredth day of the disease, and in numbers varying from less than one 
per cubic centimetre to over 10,000, by various observers. 
The histological structure of the blood in the first few days of infection 
is characterised by a relative polymorphonuclear leucocytosis. This, how- 
ever, soon gives place to a relative or an absolute leucocytosis, chiefly 
affecting the non - granular cells — the lymphocytes and mononuclear 
leucocytes. 
Brain . — No abnormal appearances can usually be observed. A human 
brain from a fatal case of M. melitensis septicaemia, which had during life 
shown unmistakable symptoms of cerebral irritation, I submitted to Dr 
F. W. Mott ; but he informed me that, apart from obviously post-mortem 
changes, the microscopical appearances of this organ were perfectly normal. 
In two monkeys injected intracerebrally with small doses of M. 
melitensis, of a strain that had not been exalted in virulence for this 
animal, abscess formation was observed localised to the cortex at the spot 
entered by the syringe needle. But in the majority of the intracerebral 
inoculations I have performed there has been no attempt at localisation of 
the micrococcus to the cerebral tissues. 
Some of the Italian observers — Caracciolo, Carbone, and Trambusti — 
record much more definite changes in the organs removed from M. melitensis 
septicaemia cases. Most of these I am rather inclined to attribute to post- 
mortem influences, which in Italy and Sicily so rapidly produce marked 
alterations in tissue cells. But one point on which all are agreed as being 
the most striking feature of sections not only of spleen but also of liver 
and kidney, is the presence of numerous cells which they term globuliferous 
cells, derived from the endothelium lining blood sinuses, and containing in 
their interior from one to fifteen or twenty red-blood discs. In the spleen of 
a case examined by Carbone, he says they were absolutely innumerable ; 
those containing a few blood cells only were rare, those containing from 
eight to ten were common, and some were seen containing very many more. 
These observations I have not been able to confirm. 
( Issued separately, September 7 , 1909 .) 
