PATHOLOGY OF PULMONARY DISEASES OF THE HORSE. 
65 
other words, a condition favorable to the development of gela¬ 
tinous infiltration is the white, pale atelectasis. This anaemia is 
the reason why the gelatinous infiltrated parts of the lungs are of 
a yellowish, or yellowish grey color. Rindfleiscli looked upon 
this condition as the second stadium of his atelectatic aedema, and 
designated it as inveterate oedema. According to R., a hyperaemia 
develops itself in every atelectatic part in consequence of me¬ 
chanical hindrance of the capillary circulation in such parts. 
This hyperaemia shall give occasion to the exudation of the blood 
serum in the alveolae, and condition a change in the pulmonary 
tissues which he designates as splenisation. Inveterate oedema 
is only to be distinguished from splenisation by the presence of 
hyperaemic phenomena by the latter, and the anaemia of the former 
to the continued transudation of serous fluid in the alveolae and 
the pressure of the distended alveolae upon their circumscribing 
capillaries. I do not think, however, that either splenisation or 
gelatenous infiltration owe their genesis to a mere serous transu¬ 
dation. By both inflammatory processes are present in the atelec¬ 
tatic tissue, a catarrhalic pneumonia the difference being that the 
inflamed atelectatic tissue by splenisation is hyperaemic , by gelatan- 
ous infiltration , anoemic. The splenisated and gelatinous infil¬ 
trated parts of the lungs contain not alone serous fluid, but the 
product of an inflammatory process, i. e., water which is rich in 
albuminous elements and round cells. Gelatinous infiltration 
(inveterate aedema, Rindfleisch) is therefore not the two stadium 
of splenisation, but the first as well as the last may appear idio- 
pathically, and the question now interesting our attention is, why 
at one time gelatinous infiltration, and at another splenisation de¬ 
velops in the lungs. 
I have at present only met with gelatinous infiltration by 
emaciated and worn-out horses, which were already ischaemic. It 
then makes no difference through what circumstances horses have 
become ischaemic, if from insufficient food, or from chronic disease 
processes. By such horses all parts are pale, also the atelectatic 
parts of the lungs, and the slight catarrhalic inflammation de¬ 
velops in the atelectatic parts, those changes which we designate 
as gelatinous infiltration. This grade of ischaemia present 
