BY DR. OSCAR KATZ. 543 



through the necessary inspections, but also, as stated, a control- 

 experiment on fifty rabbits in an adjacent enclosure was made, M'ith 

 the result that not a single death from " chicken -cholera " occurred 

 there. 



Two of these /o?<r rabbits were found dead (inside burrows ; carcasses 

 still well preserved) on the 16th February {i.e., somewhat loss than 

 four days after the first batch of five infected rabbits was turned 

 loose) ; the third was found dead (inside burrow ; carcass still fresh) 

 two days afterwards, on the 18th ; the fourth (inside burrow ; carcass 

 still pretty fresh) on the 23rd {i.e., somewhat less than four days after 

 the second lot of five infected rabbits was let loose). The probability, 

 therefore, is that all four rabbits became infected after the death of 

 specially infected rabbits placed with them. The answer to the 

 question, in what particular way this infection took place, is open to 

 conjecture. Considering that the evacuations of normal rabbits, dead 

 of "chicken-cholera" after either feeding or inoculation, do not, as a rule, 

 exhibit anything abnormal in their appearance ; considering, ajso, that 

 within the short time which it took, in the case of the fifteen rabbits, 

 from the time of infection until death, faeces originating from the 

 infected meals could hardly have been excreted ; and lastly, in view of 

 the negative results of a few direct experiments made by me (see pp. 

 546-548), it is far from being proved that the excrements (or the urine) of 

 the rabbits which died in the disease-division from "chicken-cholera " 

 were or must have been the vehicles of infection. On the other hand, 

 it was frequently noticed that from the nostrils of carcasses of 

 infected rabbits lying undisturbed, several days after the death of the 

 animals, a blood-stained liquid exuded. Here and there it was noticed 

 that the maggots of a small fly, and the latter itself, also ants, were 

 at work about the carcasses. All that may have yielded the means 

 for transmitting the virus. 



Control- Division, 



The number of fifty intact rabbits to be placed in this division at 

 the begiiming of the experiment, was at that date short of twelve ; two 

 died in the enclosure a few hours after being put there. When, two 

 days afterwards, a fresh supply of rabbits came to hand, fourteen of 

 them were turned in, in order to make up for the number missing. 



At the conclusion of the experiment only twenty-one live rabbits were 

 left over, twenty-nine having died, partly inside, partly outside the 



