64 DISEASES OF SWINE AND OTHER ANIMALS. 



white thread-like worms and myriads of microscopic eggs. In every 

 case the lobules to which such obstructed air -tubes led were red, con- 

 gested, and solid, or, as in one or two instances, dropsical, and of a 

 slightly translucent, grayish color. Sections of the diseased i)ortion 

 showed the air-cells partially filled with an exudate in which small 

 rounded cell-forms predominated. The walls of the air-cells were the 

 seat of congested and blocked capillaries and granular cells, while in 

 most cases there were superadded the more specific characters of the 

 fever — the i:)resence of the worms and their irritation having evidently 

 determined the lesions of the specific fever to the infested lobules. 



The worms may be thus shortly described : Head slightly conical ; 

 mouth terminal, small, circular, with three j)apilliB ; body like a stout 

 thread, white or brownish, skin nonstriated ; oesophagus short, 0.G3 mil- 

 limeters, enlarged posteriorly, club-shaped (Plate XIII, Fig. 4); intes- 

 tine shghtly sinuous, and longer than the body ; anus opening on a 

 papilla a little in front of the tail. 3fale, 8 to 9 lines in length 5 tail 

 curved, furnished with a bilobed membranous pouch supx)orted by five 

 rays, two of them double, and two long delicate spicula3 with transverse 

 markings (see Plate XIII, Pig. 5). Female, 1 to 1^ inches long ; tail 

 turned to one side, narrowing suddenly to be i)rolouged as a short, cui-ved, 

 conical i)oint ; genital orifice in the anterior half of the body, yet close 

 to the middle ; oviducts very much convoluted. The ova are shghtly 

 ovoid 5^ inch in diameter, and appear as if they filled the entire body 

 of the adult female (see Plate XIV, Figs. G, 7, and 8). 



Habits. — Like other strongyli, these worms attain sexual maturity in 

 the body of their host, and they lay their eggs in the bronchia, to be 

 carried out in all probability and hatched in pools of water and moist 

 earth. It is worthy of note that though I foimd in the bronchia and air 

 cells eggs in all stages of segmentation, and those containing fully-formed 

 embryos, I did not find a smgle free embryo worm. The presumption 

 is that, like other closely related worms, they are only hatched out of 

 the body, and that the microscopic embryos live for a variable length of 

 time in water or moist earth, and on vegetables, to be taken in with 

 these in feeding and drinking. 



That these worms are injurious there can be no doubt. Pigs infested 

 by them thrive badly, and many die, as did the poorest of my first ex- 

 perimental lot. Like all parasites, they midtiply rapidly wherever their 

 propagation is favored by the presence of large herds of swine, and es- 

 pecially if these are kept on the same range and water season after sea- 

 son. In such circumstances they will produce a veritable plague, prov- 

 ing especially destructive to the younger pigs. There is httle doubt 

 that many outbreaks of alleged hog-cholera, in which the lungs alone 

 are affected, are but instances of the ravages of these lung- worms, but 

 that they are the cause of the specific fever which v.e are investigating 

 is negatived by the complete absence of these worms in all of my sec- 

 ond experimental lot. 



Tncoceplialus Dispai {Crcjylin) WMp-Worm of Sicinc. — This I found 

 in large luimbers in the caecum and colon of the experimental pigs, and 

 especially of the first lot — those that had been fed on raw ofial. This 

 worm is characterized by a long, delicate, filiform anterior ])art of the 

 body, and a short, thick, posterior portion. The narrow portion is 0.02 

 milhmeters broad and exceedingly retractile; the posterior portion 

 may be almost 1 millimeter thick. The tegument is very finely striated 

 across, and has a longitudinal papillated band. The oesophagus is vei-y 

 wide and slightly tortuous. The male is about li inches long but the thick 

 portioii does not much exceed ^ inch, and is curved in a spiraL The 



