Infantile Paralysis or Acute Anterior Poliomyelites 243 



The experiments referred to were carried on during the summer of 

 1912 and in September Dr. Rosenau announced that the disease was 

 transferred by the bite of the stable-fly. 



A monkey infected by inoculation was exposed to the bites of 

 upwards of a thousand of the Stomoxys flies daily, by stretching it 

 at full length and rolling it in a piece of chicken wire, and then placing 

 it on the floor of the cage in which the flies were confined. The flies 

 fed freely from the first, as Well as later, after paralysis had set in. 

 Alternating with the inoculated monkey, healthy monkeys were 

 similarly introduced into the cage at intervals. New monkeys were 

 inoculated to keep a supply of such infected animals and additional 

 healthy ones were exposed to the flies, which fed willingly and in 

 considerable numbers on each occasion. "Thus the flies were given 

 every opportunity to obtain infection from the monkeys, since the 

 animals were bitten during practically every stage of the disease 

 from the time of the inoculation of the virus till their death follow- 

 ing the appearance of paralysis. By the same arrangement the 

 healthy monkeys were likely to be bitten by flies that had previously 

 fed during the various stages of the disease on the infected monkeys. 

 The flies had meanwhile enjoyed the opportunity of incubating the 

 virus for periods varying from the day or two which usually elapses 

 between consecutive feedings, to the two or three-week period for 

 which at least some (although a very small percentage) of the flies 

 lived in the cage." 



"In all, twelve apparently healthy monkeys of a small Japan 

 species were exposed to the flies in the manner described for the in- 

 fected monkeys. Some were placed in the cage only once or twice 

 and others a number of times after varying intervals. These ex- 

 posures usually lasted for about half an hour, but were sometimes 

 more protracted. No results were apparent until two or three 

 weeks after the experiment was well under way, and then in rather 

 rapid succession six of the animals developed symptoms of poliomye- 

 litis. In three, the disease appeared in a virulent form, resulting 

 in death, while the other three experienced transient tremblings, 

 diarrhoea, partial paralysis and recovery." Brues, 1913. 



Very soon after the announcement of the results of experiments 

 by Rosenau and Brues, they were apparently conclusively confirmed 

 by Anderson and Frost (1912), who repeated the experiments, at 

 Washington. They announced that through the bites of the Stomoxys 

 flies that had previously fed on infected monkeys, they had succeeded 

 in experimentally infecting three healthy monkeys. 



