THE HORSE. 199 



complicated portion of the lun^s must first be ai7'Iess before the 

 inthmimatory processes take pUice. The atelectatic parts have a 

 more or less liomo^eneous character, and, when they become filled 

 with this riuid substance, they have the above-mentioned gelatinous, 

 pelhicid character. The atelectatic parts are rendered oidematous by 

 the intlammation ; fluid and cells distend the alveoli instead of air; 

 such parts are tense, yet elastic to the touch. AVe have, then, atelec- 

 tasis — airlessness — plus inflammatory cedema." 



" It may be remarked that we have two forms of cedema : the 

 one mechanical, due to some interference with the circulation, by 

 which the vessels become so distended that the serous elements of 

 blood exude thro\igh the vessels; this is exemplified by the collat- 

 eral a''lei/ia, which often takes place in the non-complicated parts of 

 the lungs in pneumonia, that causes death by a sort of internal 

 self -drowning. The other is due to inflammation, which you should 

 know all about."' 



2. " A second condition proper to gelatinous infiltration is ana3- 

 mia ; or, in other words, bloodless atelectasis is a sine qua no)i to ge- 

 latinous infiltration. This anajmia is the reason that such parts 

 have a yellowish or yellowish-gray color. According to Rindfleisch, 

 a hypenvmic condition develops in every atelectatic part. This 

 hyperoimia is the cause of the exudation of the blood-serum in the 

 alveoli, and causes a condition which he names splenization. His 

 * inveterate cedema ' is only to be distinguished from splenization 

 by the absence of hypenemia, and the anaemia by the pressure 

 caused by the continued transudation of fluid into the alveoli." 



According to Schutz, neither splenization nor gelatinous infiltra- 

 tion are due to mere serous transudation. Both owe their genesis 

 in atelectatic tissues to inflammation, except in splenization the ato- 

 lectasic tissues are in a hypersBinic, while in gelatinous infiltration 

 they are in an ancemic condition. The splenized and gelatinous 

 infiltrated tissues contain not only serous fluid, but the products 

 of inflammation, i. e., water, which is rich in albumen and cellular 

 elements. Gelatinous infiltration is, therefore, not the second stiige 

 of splenization, as Rindfleisch asserts, but either can occur 8ui gene- 

 ris, and we have therefore to consider why at one time we have 

 gelatinous infiltration and at another splenization of the lung. 



" I have only seen gelatinous infiltration in emaciated and weak 

 liorses, which were anremic. It makes no diflference whether this 

 latter condition was produced by poor dietetic conditions or chronic 

 disease. In such horses all parts are pale, also the atelectatic por- 

 tions of the lungs ; and slight catarrhal processes in such parts easily 



