102 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



together with the hypothesis based on these observations, that 

 Stomoxys calcitrans might be responsible for the spread of poU- 

 omj^htis, aided possibly by other blood-sucking flies. During the 

 summer of 1912 an attempt was made by Prof. M. J. Rosenau of 

 the Harvard Medical School and the writer to transmit the dis- 

 ease experimentally through the agency of Stomoxys, using mon- 

 keys for this purpose, as these animals are susceptible to poliomyelitis. 

 The successful outcome of this work was announced in September, 

 1912, '^ and was soon afterwards confirmed by Doctors Anderson and 

 Frost of the Public Health and Marine-Hospital Service, who repeated 

 the same experiments with similarly positive results. ^ 



Infantile paralysis was first recognized as a distinct disease in 1840 

 by Heine, a German surgeon who found that the spinal cord was 

 the site of attack. Many years later, Striimpel in 1848, suggested 

 that the lesions in the cord were caused by an infectious agent, and 

 in 1890 Medin published the first good clinical account of poliomyelitis. 

 Within the last ten years, Wickman in Sweden and various others, 

 both in Europe and America, have investigated the disease with great 

 care, so that its clinical,' epidemiological and pathological aspects 

 are well known. 



The living organism which causes the lesions in the spinal cord is 

 not known, but it has been demonstrated to be an ultravisible virus 

 which passes through a Berkefeld filter only with difficulty, suggesting 

 that it is just beyond the range of visibility.^ Its pathogenic activities 

 are mainly restricted to the anterior portions of the spinal cord where 

 the motor nerves take their origin, and the resulting degeneration 

 of these motor nerves produces a more or less complete paralysis of 

 the corresponding muscular elements. The arms and legs are most 

 frequently affected, although paralysis of many other muscles is 

 common in varied combinations, sometimes bilateral or unilateral, 

 but often irregular in distribution. In fatal cases, death usually 

 results from a paralysis of the respiratory muscles and consequent 

 asphyxiation. The actual mortality is rather low, averaging from 12 

 to 17 per cent, when only typical, paralytic cases are considered. In 



1 Rosenau, M. J. and Brues, C. T. Some Experimental Observations upon 

 Monkeys Concerning the Transmission of Poliomyelitis through the Agency of 

 Stomoxys calcitrans. Bull. Mass. State Board Health, Sept. 1912, pp. 314-317. 



2 Anderson, J. F. and Frost, W. H. Transmission of PoUomyeUtis by Means of 

 the Stable fly, Stomoxys calcitrans. Public Health Reports, Vol. 27, No. 43, pp. 

 1733-1735. . (October 1912.) 



'Since this article was written, Flexner and Noguchi (Journ. Amcr. Med. Assoc, 

 February 1, 1913) have obtained m cultures, extremely minute bodies of variable 

 size and appearance which they believe may be the causative organism. This, 

 however, is still somewhat in doubt. 



