^S3 



•'and they sickened with t\'pical symptoms of septic 

 " fever, but whilst A completely recovered, B died in 

 " a few days, presenting the characteristic signs, 

 "enlarged spleen, infilterated with nodules and 

 " swarming with typical bacteria, which were plentiful 

 " throughout the other organs and the blood." '•' 



Here we see, first, how little effect the parasites 

 had on the birds so long as their diet was only seed, 

 and secondly, how much effect the egg had in the 

 direction of stimulating the bacteria to the extent 

 of a fatal virulence. Special note must be taken of 

 the fact that B was fed in both experiments on food 

 contaminated with merely A's excrement. In the 

 second one. A, on a diet comprising egg, was given 

 some bacteria derived from an ^'g<g culture. This 

 produced an attack of one of the types of Septicaemia, 

 which made him very ill, but from which he ultimately 

 recovered. The bacteria which were the source of 

 his trouble had been bred, I believe, at a temperature 

 of about 60''. Anyhow 100° would be the highest to 

 which they had been exposed. Now mark what 

 happened — the bacteria descended from those, and 

 developed in the ^%% food in A's intestines at a 

 temperature of anything betw^een 110° and 114°,! and 

 then transferred to B simply through the medium of 

 the former's excreta, had, by reason of their develop- 

 ment and life in the great heat of a sick bird's bod}^ 

 become of such intense virulence that B was speedily 

 killed. That the latter as well as the former was 

 being fed on ^%<g was also a factor in the result. 



Can we any longer wonder how the epidemics of 

 what is (in some quarters) still called "tuberculosis" 

 are caused, and why during the epidemics the tj^pe of 

 the disease increases from a comparatively mild 



* Fur and Feather, Reprint from, 1898. 



t During acute illness the bodily temperature alwaj's rises, sometimes 

 as much as 5® or 6®. 



