678 REPORT OP THE COMMISSIONER OF AGRICULTURE. 



gerous, inasmucli as a new disease may tlius be introduced into our 

 country from abroad. 



The iraijortant lesson taught by these investigations lies on the sur- 

 face. Infectious diseases in wliich the gross pathological effects dif- 

 fer quite constantly in the same species of animals should not be 

 classed as identical until so proved by the most rigorous methods 

 that scientific research possesses. 



On page 226 of the Second Annual Report of the Bureau (1885) a 

 brief mention was made of a disease found once by Loffier in Ger- 

 many, which presented as the most marked lesion an enormous oedema 

 or swelling of the skin of the neck. It is caused by small ovid bac- 

 teria, calling to mind by their apjDearance the organisms of septi- 

 caemia in rabbits, especially when in the process of division, although 

 but half as large. Inoculation with these bacteria produced speedy 

 death in rabbits, mice, and guinea-pigs, as well as ings. Rabbits died 

 within twenty-four hours; mice lived a few hours longer; guinea- 

 pigs died on the second and third day after inoculation. In all ani- 

 mals there was a sero-sanguinolent effusion into the sul^cutaneous 

 tissue of the entire abdomen, extending to the axilla on the one hand 

 and the inguinal region on the other. Muscular tissue infiltrated 

 with the same reddish effusion. Pigeons, fowls, and rats remained 

 unaffected after the inoculation. One of the three inoculated pigs 

 died on the second day with the following lesions: " Skin of abdomen 

 bluish red. Enormous oedema of the skin. Lungs hypostatic. Mu- 

 cosa of stomach deeply reddened. Spleen unchanged. Kidneys par- 

 enchymatous. Mesenteric glands not swollen."* 



More recently this same infectious disease among swine in Ger- 

 many has been carefully described and studied by Schutz,t and as it 

 has many features in common with the disease which has been sep- 

 arated from hog-cholera in the preceding pages, it deserves a some- 

 what careful analysis here. 



The author first obtained the microbe causing this disease by plac- 

 ing beneath the skin of small animals bits from spleens of pigs wnich 

 had presented symptoms of rouget. The spleens were putrid, but 

 the pathogenic microbe was found alone in the bodies of the inocu- 

 lated animals, J the f)utref active germs not having the power of pen- 

 etrating beyond the wound in which they are placed. In this way he 

 inoculated 2 mice, 2 guinea-pigs, 1 pigeon, and 1 rabbit. The mice 

 died on the second and third day. The bacteria found in the organs 

 of these mice have the form of ovals, and are easily stained by watery 

 solutions of aniline colors. 



When stained witli gentian violet they show in their central portions an unstained 

 region surrounded by a layer stained blue. The thickness of this layer is greater 

 at the poles, so that the extremities apjiear more deeply <^tfiined than the sides. 

 When deeply stained they appear uniformly blue. As these organisms stand be- 

 tween microoococci and baeilli. tliey may be called bacteria. They aie 1.3""" long 

 and .4""" to . S""" broad. T] ley multiply iii tlie iollowuig mamier : They Ijfcome twice 

 as long as broad, show diKtinctly rounded extremities, and stjiin hke'the organisms 

 of rabbit septicaemia and fowl-cholera, so that bet%\'een the deeply stained ends about 

 one-lialf or a thii-d of the entire length remains unstained. Careful examination 

 shows, however, that the colored end pieces are connected with eueh otlier liy v, fine 

 line which passes from one to another on each side. The end pieces tlien separate 

 and the median portion disappears. The former are at fust spherical, but very soon 



* Arbeiten a. d, kaiserlichen Gesundheitsamte, I, S. 877. 

 + Loc. cit. S. 376. 



I The bacteriiim of hog-cholera as found in Nebraska was obtained pure in the 

 same way as described elsewhere in this report (p. 638). 



