482 



Sambon reports a periodical character different from this 

 observed in Illinois in the fact that it relates to an increased 

 activity of pellagra — an intensification of its symptoms in indi- 

 vidual pellagrins — occurring in spring and in fall, coincident, 

 as he says, in Italy with the time of flight of two generations of 

 the sand-flies ; and he uses this fact to support his hypothesis 

 of the dependence of the disease on the insects. Assuming that 

 pellagra is produced by a protozoan parasite, he further assumes 

 that the aggravation of symptoms twice each year is due to a 

 migration to the surface of this hypothetical parasite, which is 

 thus exposed to be taken up by the sand-flies as they draw blood 

 from the skin of pellagrins. The summer and fall recrudescences 

 of the disease he thus connects with the summer and fall abun- 

 dance of the sand-fly imagos. His periods are, however, difterent 

 from ours, the first coming in March or April instead of May and 

 June, and the second in September or October, instead of August 

 as in Illinois. I have not been able to learn from our physicians 

 that any periodicity similar to this described by Sambon has 

 been noticed in Illinois cases, but if it has it would be impossible 

 to correlate it with the facts above described concerning the 

 development of Simulium in our «State. 



There are other interesting points of contrast between our 

 Illinois conditions and conclusions and those obtained by a 

 study of the problem in Italy and in other parts of Europe. We 

 are told, for example, that in Italy pellagra is a rural disease, 

 to which town-dwellers are virtually immune, even where there 

 is free communication between the town and adjacent pellagrous 

 districts ; but in Illinois we have every year several deaths from 

 pellagra in our largest city, with a population of more than two 

 million souls. Four cases of this disease have lately been 

 reported to me from the private practice of Dr. Oliver S. 

 Ormsby, Secretary of the State Pellagra Commission, the 

 sufferers from which had lived continuously in Chicago for years. 

 Pellagra, in fact, can scarcely be said to be with us, as yet, a 

 rural disease, the asylums in which 96 per cent, of the known 

 new cases have occurred being in or very near cities and towns, 

 and all cases reported from outside such institutions having 

 come from the town and not from the country. The Peoria 

 asylum, containing sixty-three of our known pellagrins, is in a 



