io8 THE GROUSE DISEASE chap. 



certain antiseptic media or other substances ; whereas 

 if spores are formed by the bacilli, the application of 

 such conditions would be altogether productive of'a 

 different result. 



Now the experiments of feeding which have been 

 recorded in the preceding chapter point strongly to 

 the absence of spores, because if such were present in 

 the intestinal contents, or in the cultures used for 

 the feeding, the positive results would have been more 

 numerous than they have actually been. But these 

 results do not absolutely demonstrate the incapability 

 of the bacilli of forming spores, and for these reasons : 

 under natural conditions the fowls, just as in fowl 

 cholera, contract infection most probably by picking 

 up food from a soil tainted with the evacuations of 

 birds affected with the disease ; and it might be pos- 

 sible that the bacilli on and in the soil produce 

 spores, but they do not do so within the living body 

 of the animal, or in the artificial cultures that had 

 been used. 



A careful microscopic examination of old cultures 

 shows that there are present numerous bacilli which, 

 from their swoUen-up condition and their abnormal 

 shape (spindle-shaped and abnormally thick), are no 

 doubt comparable to involution forms. Besides there 

 are present numerous bacilli which, from their not 

 taking the stain, compare to dead bacilli, of which 



