17 



Harvard Alumni Bulletin. XY. Xo. 9. Nov. 20, 1912. pp. 140-142. 



Ad account of the methods by which the discovery of Rosenau 

 and Briies was reached is g-iveii in the above. Careful tabulation 

 of cases of poliomyelitis in the State of Massachusetts showed 

 that these occurred during the summer and early autumn, grow- 

 ing more frequent after the middle of the summer and lasting 

 until well on towards cold Aveather. The number of isolated cases 

 was so great that contact was soon seen to be at least an improb- 

 able means of transmission. The possibility of the existence of an 

 insect carrier was then considered. Fleas and bed-bugs were 

 ruled out because cases occurred in houses in which these insects 

 were conspicuously absent. Other biting insects were excluded 

 because no history of their presence was found. 



The common stable fly (so-called in the U.S.A.), Stoinoxys 

 calcitrant, was the only one whose distribution agreed with that 

 of the cases. Healthy monkeys were then infected with the 

 disease, they having long been known to be subject to it. These 

 were then allowed to be bitten by Stovioxys and a large number 

 of the flies, presumed to have taken up the virus from the infected 

 monkeys, were introduced into a suitable cage containing the 12 

 monkeys referred to in the previous abstract ; six of these became 

 infected and exhibited the symptoms of the disease. Further 

 confirmation was obtained by Drs. Anderson and Frost, of the 

 Public Health and Marine Hospital Seiwice at Washington, who 

 infected another set of healthy monkeys with a culture from those 

 bitten by the flies and reproduced the disease in them. 



The normal food of Stoniowys calcitrans is blood obtained from 

 various animals, but less commonly from human beings. Cattle 

 and horses are chiefly attacked, and the flies are in consequence 

 Luore common in the country than in towns. Each fly appears to 

 feed once in every two or three days, perhaps oftener. They 

 remain out-of-doors in fine weather and seek shelter in rain, but 

 l)ite more commonly outside in bright sunny weather. Stoinoxys 

 appears early in the spring and becomes more abundant after 

 midsummer, persisting after the house-fly has begun rapidly to 

 disappear. The proboscis, which can be observed when the fly 

 is at rest, distinguishes it at once from the house-fly, to 

 which it has, for the ordinary observer, some superficial resem- 

 blance. The breeding habits resemble those of the house-fly. The 

 eggs are laid in small masses in fermenting heaps of grass and 

 straw, horse manure, cow dung and even garbage. Excessive 

 moisture seems favourable to the development of the larvae. 

 Stonio.rys calcitrans is very widely distributed throug^hout the 

 world, but is the only member of its genus in the New World. 

 It has been known in America for a long period, and though 

 possible, it seems hardly probable that it is an importation. 



Howard (C. W.) ii.-_ Clakk (P. F.). Experiments on Insect Trans- 

 mission of the Virus of Poliomyelitis. — .//. of E,vp. Med. XYI. 

 No. 6. 1912. pp. 850-859. 



The authors made careful experiments with the house-fly, 

 Musca domestica, and with mosquitos, Cvlex j^'pi^^^-^ in two 

 28112 B 



