Anatomical Changes. 73 



the species of the parasites, the duration of the process, etc. 

 As a rule, airless foci are found in the otherwise normal or em- 

 physematous and pale lung tissue, preferably in the anterior 

 and inferior portions of the lungs, from the size of a pea to that 

 of a walnut. These foci are generally wedge-shaped, with the 

 base on the pleural surface and the apex directed toward a 

 larger bronchus. The foci are either sunken in and like meat 

 (atelectasis) or more or less prominent, doughy, soft to tough, 

 according to the duration of the process. They are reddish or 

 grayish red, or even grayish yellow in color (worm-nodules, 

 bronchopneumonia verminosa lobularis). On section these foci 

 discharge a thick, reddish fluid which contains epithelia, pus 

 corpuscles, ova, embryos and fragments of adult worms. 



Not uncommonly extensive inflammatory areas are encoun- 

 tered, especially in certain species of animals (goats, sheep, 

 (•'lives and field hares), which are confined either to one or excep- 

 tionally to several lobes (l)roncliopneumonia verminosa lobaris 

 sive diffusa). The affected portions of lung are like the spleen 

 in color and consistency and they show on section dark red to 

 black-red hemorrhagic spots, also dirty gray, crowded, even con- 

 fluent spots. The expressed juice contains a large number of ova 

 and w^orm embryos. In acute cases in calves the exudate often 

 has a fibrinous character. In certain cases, the lungs contain 

 vesicular nodules (as a rule, situated under the pleura) from 

 the size of a millet seed to that of a hemp seed, which are found 

 toward the apices and margins and wdiich are of tough consist- 

 ency (bronchopneumonia nodularis pseudotuberculosa s. alveo- 

 litis nodularis verminosa). These nodules are formed around 

 an isolated, fully developed strongylus capillaris or a strongy- 

 lus commutatus, or around aspirated ova. The nodules are 

 light yellow to gray yellow in the presence of Str. capillaris, and 

 red-brown to violet or blackish in the presence of Str. commu- 

 tatus. After the death of the worms, the nodules undergo casea- 

 tion and finally calcification. 



In dofJH piiihead-sized, translucent, pearl-like, exceptionally larujer, broncho- 

 pneumonic foci are formed at the root of the lunjo^s, sometimes also in other places; 

 they are produced by the ova or embryos of Str. va?orum. In the presence of 

 Str. pusillus the lungs of the eat show a similar picture; the embolic transportation 

 of embryos of Ollulanus tricuspis produces nodules similar to miliary tubercles with 

 a hepatized pulmonary parenchyma in their neighborhood. 



The bronchi contain an abundant mucoid or nnicopurulent 

 secretion, sometimes streaked with blood, in which the sexually 

 mature worms are found. Under the microscope numerous ova 

 and embryos are seen. One frequently sees the first worms at 

 the end of the trachea, i. e., at its bifurcation, and these may 

 completely obstruct the larger or the medium-sized bronchi, 

 in dense masses, which sometimes contain only a few or no 

 worms at all. The mucosa is swollen, reddened and sometimes 

 streaked with hemorrhages. Bronchiectases of varying sizes 

 are rareh- missed in the presence of worms. 



