COMPARATIVE PATHOLOGY. 
65 
tary follicules of tuberculosis. Indeed, one finds in the center of 
each nodulous nucleus an egg or embryo lodged in a giant cell. 
This last is surrounded by a crown of epithelial cells, more or 
less abundant, and by an external ernbryoneal zone which fre¬ 
quently has a tendency to become fibrous. 
The details already mentioned upon the habits of the 
strongyli, in the different stages of their development, would be 
sufficient to prove that the cellular group formed by the giant 
cell, and its surrounding of epithelial cells, have an intra-vascular 
origin, and proceed from the endothelium of the obliterated 
vessel. But again, one might quite frequently observe the con¬ 
tinuity of this last with the follicles, and to see that its size is 
suddenly increased at the point where the giant cell is; it is even 
possible to detect the preliminary alterations which arrive to the 
formation of the follicle. At some distance from this the vascu¬ 
lar endothelium is hypertrophied, and its elements project on the 
inside of the vessel. In the neighborhood of the follicles these 
proliferate, and form a column of epithelial cells in continuity 
with those which surround the giant cell. 
There is no doubt, then, that this is a nodular arteritis, with 
the structure of the elementary follicle as described by Mr. 
Kiesser, under the name of miliary tuberculous aneurism , or 
enveloping nodule (nodule engainant). 
I will add that the preceding phenomena, taking place 
most ordinarily upon vessels closed to each other, form compound 
nodules which would have the greatest analogy with the tubercu¬ 
losis, plexiform angioma of the same other, if their development 
had taken place round blood vessels of new formation. 
Evidently the vascular theory of the follicle rests on ground 
sufficiently important to be definitively accepted as scientific; 
and the above named results add a strong weight to the experi¬ 
ment of Mr. Martin upon experimental tuberculosis. 
Spontaneous reproductions, still artificial, of the tuberculous 
follicle, under the influence of the ovoe of the nematode, brings 
us to the conclusion, already admitted, viz.: the negative of the 
anatomical specificity of tubercle. 
Accordingly, I am brought to the following conclusions: 
