548 EXPERIMENTAL RESEARCHES WITH CHICKEN-CHOLERA MICROBES, 



the caretaker on Rodd Island, it was found dead there, June 6th. 



It had been burnt when I visited the Island. His description of the 



condition of the carcass did not lend any support to its having 

 succumbed to " chicken-cholera." 



Besides, the result of another experiment showed that urine, 

 taken from a rabbit newly dead in consequence of inoculation 

 with virulent culture, had no effect on fresh rabbits which were 

 inoculated with it. 



1888. 

 September 11th, 1.30 p.m. 

 Two rabbits received subcutaneously about iccm. (2 minims) of 

 such urine. The bladder of the rabbit from which the latter was 

 obtained was much distended. The deep amber-yellow urine, 

 which contained much firm matter (urates), was derived by means 

 of sucking a small portion into a sterile glass-tube, through a little 

 hole made by a hot glass rod into the lifted and stretched vertex 

 of the bladder. 



Results : 



One rabbit was found dead at 7.30 a.m., September 13th. P.M., 

 Negative. 



The other remained alive. 



Transmission op the Virus op Chicken-cholera through 

 Rabbits in Successive Generations. 



It being from a theoretical as well as from a practical point of 

 view — in case the microbes of chicken-cholera were to be employed 

 as a means for the destruction of rabbits in Australasia — a matter 

 of some importance to know whether these microbes, by passing 

 through the bodies of rabbits in a number of continuous genera- 

 tions, become altered in their degree of virulence or not, it was 

 decided that such an experiment, with a view to obtaining the 

 required information, should be made, extending to the number of 

 twenty successive transmissions from rabbit to rabbit. 



Let us suppose the virus under consideration is endowed with 

 the faculty of becoming more virulent, or, in other words, of 



