64 
M. LANLAINK. 
It is in these central parts of the pulmonary circulation that the 
strongyli copulate. The fecundated eggs are transported, as they 
are hatched, in the finest and farthest divisions of the vascular 
ground of the artery where the adults are; that is, in the 
arterials, with a single layer of muscular fibres, or in the 
capillaries. It is there that they undergo the phases of then- 
development. The embryos hatch in the interior of the arte¬ 
rials or of the capillaries, and soon emigrate towards the smallest 
bronchi, where they are found in great number under sections 
made for the microscope. 
The presence of the embryos in the bronchi, which has not 
yet been mentioned, allows the legitimate supposition that they 
are expelled by the respiratory channels, to he afterwards acci¬ 
dentally introduced into the digestive apparatus of another dog. 
I am continuing the experimental verification of this supposition, 
suggested by preceding observations. 
The lungs, whose vessels are filled with strongyli, are filled 
with grey granulations, semi-transparent, prominent, which give 
to the surfaces of section a rough aspect and realize, by their 
physical characters and their large number, all the appearances 
of granules. We must mention an important peculiarity relat¬ 
ing to the localization of the parasitic granulations, which are 
seen to. gather at the base of the pulmonary lobes, and are m 
smaller number going towards the apex, where they disappear 
almost entirely. 
This localization, different from that of the lesions of tuber¬ 
culosis, with the so well-known immunity of canines to spon¬ 
taneous phthisis, is sufficient to prevent all mistake. 
I have successively studied the histological characters of this 
pseudo tuberculosis, overlooked to this day, and the results I have 
arrived at belong to the discussion which goes on now relating to 
the anatomical specifity of tuberculosis, and its pathogeny. I 
will only mention of my observations the most general facts and 
the conclusions which derive from it. 
The ova or embryos stopped in the fine arterials become the 
starting point of a nodulous arteritis , possessing in its structure 
all the characters which , since Koster , are granted to the elemen - 
