150 POULTRY DISEASES 



filtrate and incubated seventy-two hours and no growth of 

 germs occurred on any of the tubes; this shows that all visible 

 germs were taken out. Smears of the filtrate were made 

 and stained and an examination of these likewise gave nega- 

 tive results. In none of these inoculations did roup appear. 

 So far as this one experiment goes, it appears that our type 

 of roup is not due to an ultramicroscopic germ. This type 

 of roup is quite contagious. 



Marx produced a yellowish-diptheritic membrane by inject- 

 ing pox emulsion into the mucous membrane of the mouth 

 and eye of a bird. 



The report of the United States Bureau of Animal Industry 

 for 1910 an account of the isolation of the Bacillus necro- 

 pfiorus from the ulcers in one outbreak (this is the germ 

 that causes necrotic stomatitis in hogs and sheep, gangerous 

 dermatitis in horses, diphtheria in calves, and many other 

 pathologic conditions in other animals), in another outbreak 

 the Bacillus avisepticus (the germ of fowl cholera) was found, 

 and in still another outbreak a coccidium appeared to be the 

 cause. The Bacillus injocyancus has also been isolated by 

 another investigator as has also a short, rod-shaped germ 

 with rounded ends called the Bacillus cacosmus. It would 

 thus appear that several germs play a more or less im- 

 portant part in the causation of roup. Other germs have 

 been reported from time to time as having been associated 

 with this disease, so that with the reports before us from 

 scientific laboratories we cannot point, as yet, to any certain 

 germ as the cause. 



Mode of Spread.— This disease is spread by birds 

 introduced into a flock from infected premsies, and 

 by exposure, as at poultry shows. A chronic type 

 of the disease in one or more birds (carriers) in a 

 flock may serve to infect others when they are 

 weakened by predisposing causes, as by exposure 

 to cold or dampness, or by roosting in a draught, 

 or in badly ventilated buildings. 



Symptoms. — There are three forms of the dis- 

 ease, that is, three forms of lesions. Any or all 

 may be present in the same bird. 



1, The nasal type.— This type is characterized 

 at first by a thin, watery discharge with an offens- 

 ive odor characteristic of roup. Later the ca- 

 tarrhal product becomes somewhat thicker (muco- 

 purulent) and the nostrils become occluded (glued 



