368 POLIOMYELITIS [CH. 



at the same time exposing twelve healthy monkeys to the bites 

 of these flies. Of these twelve monkeys, six developed symp- 

 toms characteristic of poliomyelitis, namely, illness, followed 

 by more or less extensive paralysis. Two monkeys died, and 

 in the spinal cord of one of them was found the characteristic 

 lesions of this disease, i.e., perivascular infiltration and des- 

 truction of the motor cells of the anterior cornu. 



Anderson and Frost have confirmed these experiments of 

 Rosenau and their results will be given in detail. On October 

 3rd, a rhesus was inoculated intracerebrally with an emulsion 

 of the spinal cord of a monkey that had died of poliomyelitis. 

 Two hours after inoculation it was exposed to the bites of about 

 300 Slomoxys collected in Washington. Each day until the 

 death of the monkey on October 8th, it was exposed for about 

 two hours to the bites of these flies, together with additional 

 ones that were added as they were caught. This monkey 

 developed the characteristic complete paralysis on October 

 7th and died on October 8th. Another monkey similarly 

 inoculated on October 5th was then daily exposed to the bites 

 of the same lot of flies from October 7th until October gth, 

 when the second monkey died. Thus from October 4th to 

 the gth inclusive, the Stomoxys had been able to feed on two 

 monkeys infected with poliomyelitis. 



Beginning on October 4th, two fresh monkeys (Java and 

 rhesus) were exposed daily for about two hours to the bites of 

 these same flies ; and on October 5th yet a third monkey 

 (rhesus) was similarly exposed. On October i2th the Java 

 monkey was found completely paralysed and died the same 

 day. The second rhesus monkey also developed paralysis 

 during the day and was anaesthetised. The first rhesus monkey 

 died on October I3th after presenting the typical symptoms of 

 poliomyelitis. 



Thus three monkeys exposed daily to the bites of several 

 hundred Stomoxys, which at the same time were allowed to 

 feed on two infected monkeys, developed typical symptoms 

 of poliomyelitis seven, eight and nine days, respectively, from 

 the date of their first exposure to the bites of the flies. 



These results are of great interest and shew that the 



