144 Veterinary Medicine. 



Not only does the milk vary so widely with the genera, but 

 that of the ruminating animal with its great excess of casein 

 coagulates in the stomach into large dense clots which are not 

 easily penetrated and digested by the peptic juices while that of 

 woman or soliped forms loose clots, easily permeable by the gastric 

 fluids and therefore much more readily digestible. Indeed the 

 milk of these monogastric animals often forms loose floating 

 flocculi only, instead of solid clots. As cows are usually selected 

 for foster-mothers to the orphaned animals of other genera this- 

 becomes a source of danger to the young and must be obviated 

 by modifying the milk more in keeping with that of man or 

 soliped. 



As predisposing causes, must be named a weak constitution 

 and damp, dark, filthy, or otherwise unwholesome buildings. 

 Buildings with no drainage nor ventilation beneath the. floors, 

 standing on filth-saturated soil, and those with double walls 

 holding dead rats and chickens are especially to be dreaded. In 

 breeds of inconstant color the lighter colored calves (light yellow, 

 light brown) are more subject to such attacks than the darker 

 shades (dark browns, reds, blacks). The weak constitution may 

 be the result of close breeding, without due consideration of the 

 strength and vigor of the parents. Then young animals kept 

 indoors in impure air, damp and darkness are more susceptible 

 than those that are kept in pasture and are invigorated by exer- 

 cise, pure air and sunshine. 



Aside from the general run of causes, predisposing and exciting, 

 we must recognize the contagious element. Jensen has sought to 

 identify the microbe as a small ovoid bacillus united in pairs, or 

 in long chains. This was present not only in the ingesta, but in 

 the lesions of the mucosa, and in the lymph glands. Its cultures 

 ingested in milk, or injected into the rectum sometimes produced 

 the affection. Microscopically it resembled the bacillus fcetidus 

 lactis, but the latter failed to produce the disease. He looks upon 

 it as a sport of the bacillus coli communis. 



Perroncito found micrococci, usually arranged in pairs and com- 

 parable to the cultures of those obtained from the blood in the 

 pneumonia of calves. The injection of the cultures into the 

 thorax of a Guinea-pig caused pleuro-pneumonia with or without 

 dysentery. The rabbit proved immune. At the necropsy the 



