22 



of a young bouillon culture in from i8 to 24 hours. Dissection shows a wide- 

 spread, purulent peritonitis, with slight bloody extravasations of the peritone- 

 um. Subcutaneous inoculations' of small quantities of bouillon cultures lead 

 to hot tumors, w*hich spread quickly and in which firm, hard centres form. 

 Ihe whole tumor gradually assumes the same hard, uneven condition. The 

 skin becomes dry, cracks, splits and forms a brown, thick crust which, after 

 some time, falls ofY. Under the crust, there is an extensive, uneven yellowish- 

 white, cheese-like mass, 2 mm. to 2 cm. thick, firmly adherent to the underly- 

 ing tissue. Gradually tlhis mass falls off, and regeneration of the tissue from 

 the edges of the skin follows. The hard, cheese-like masses look exactly like 

 the croup and diphtheritic membranes of fowls and pigeons. They consist 



Fig. 24.— From the na^al secretion of hen Fig. 25.— Bodies from the under side of 



No. 6. m. Kitt's "MoUuscum bodies." a false membrane from pigeon No. 11. 



r. A red lilood cell. 



of bacteria and leucocytes, as well as of some detritus. The general conditions 

 of the rabbits is poor, so Jong as there is a hot tumor. Later, their condition 

 miproves, though the animals remain very thin in spite of being well fed. In 

 a few cases, sympathetic inflammation of the eyes, purulent conjunctivitis on 

 one or both sides, purulent panophthalmia, perforation of the cornea, etc., oc- 

 cur during tihe course of the 'healing of the local lesions. If there are no com- 

 plications, the local lesions heal in from 3-5 weeks ; if the described complica- 

 tions set in, death comes after the disease has run its course lor 1-3 months. 

 Old cultures filtered through Chamberland filters, produced, when inoculated 

 intraperitonealy, neither death nor sickness. 



Guinea Pigs. The effect of the roup bacillus was the same on these ani- 

 mals as on the rabbits. 



Mice die in 12 to 18 hours from inoculation with 1-8 to 1-4 c.c. of a bouillon 

 culture of the bacillus. Dissection shows excessive swelling of the spleen. 

 Intraperitoneal inoculation gives rise to hemorrlhagic purulent peritonitis. The 

 bacilli are present in great numbers in the exudations and spi..'en ; whilst 

 they are but seldom found in the blood. 



The effect of the roup bacillus on hens and pigeons, is shown in the fol- 

 lowing table of inoculation experiments. 



