I8l 



XLbc Storv) of 36ir&-3)catb. 



By W. Geo. Creswei.!., M.D., L.R.C.P., F.Z.S. 

 (Continued from pa^e 155). 



j^ OT only may the virulence of the septic bacillus 

 I / be enhanced by the conditions to wliich it 

 J-^-O* has been subjected during its development 

 before entering the bird's system ; that of its 

 descendants is also most certainly greatly heightened 

 by the influences attached to their environment while 

 they inhabit the alimentary canal of their host. Heat, 

 moisture, and the presence of egg- yelk are, as we have 

 seen in our artificial 'culture, the most potent of these 

 conditions of enhancement. The effects of heat have 

 been seen in the differing results when in our experi- 

 ment one culture was made at 100^ F. and the other at 

 60° F. Some amount of moisture is absolutely 

 necessary for the growth of the bacillus — we all know 

 that dried meat will keep good any length ot time if 

 carefully maintained quite dry and never allowed to 

 become in the slightest degree moist. Egg-yelk is 

 known to be one of the very best media for cultures 

 of our micro-organism. This can, as we have seen, 

 be cultivated in any dead organic matter, flesh, the 

 excreta of the body, dead leaves, broth, milk, and 

 hundreds of other materials, including of course white 

 of &g%. But in none of these does it seem to attain 

 to that vigour of pathogenic power which is induced 

 by its growth in yelk of eg^. That it should be so 

 vigorous when associated with this substance is pro- 

 bably due to the oily nature of the latter, but what- 

 ever the reason may be, the fact remains that the 

 bacillus has a special affinity for it. 



By this time my readers will not need to be told 

 that all these three conditions, which favour the 

 action of the bacillus, exist in the case of birds fed 

 upon egg-food. The Qgg is there, the moisture is 



