52 DIPTERA OF MINNESOTA. 



wearing the clothes of and using the soiled bedding taken from the 

 beds of patients who had died of this disease. The mosquitoes of 

 the district were kept away, and these brave men passed through 

 this trying ordeal safely. The transmitter of the yellow fever is 

 the mosquito known as Stegomyia fasciata. 



As stated above, we know also that the disease known as filariasis, 

 giving rise to the condition known as "elephantiasis" (not B. grac- 

 corum,) in which a limb of a human individual becomes enormously 

 enlarged, is caused indirectly by the bite of a mosquito, which forms 

 one of the hosts of a tiny parasitic worm, Filaria. The writer will 

 never forget seeing in the streets of Tangiers, Morocco, a sufferer 

 from this loathsome, leprous-like disease, his right leg enormously 

 swollen, keeping at bay a horde of heartless boys who were stoning 

 him, and taunting him for his deformity. One could almost imagine 

 he heard the biblical "Unclean !" "Unclean !" in the unintelligible 

 tongue of the Moorish lads. 



Considering the part that mosquitoes play in spreading disease, 

 is it any wonder that this family CiiHcidac, is one of intense econom- 

 ic importance? 



CHIRONOMIDAE. 



The Midges. 



These small, delicate, gnat-like flies, frequently called midges, 

 might well be referred to as "Sunset Flies," since they are wont to 

 appear in clouds just before or after sunset, preferably in damp 

 places, about water in the woods, and elsewhere, though one meets 

 with them in all localities. In the short days of autumn we fre- 

 quently see the air full of them "dancing" as it were, in the warm 

 afternoon sunshine. WilHston has seen them in the Rocky Mountains 

 at nightfall, rising in incredible numbers, so abundant as to produce 

 a humming noise like that of a distant waterfall, audible for a long 

 distance. Frequently they are mistaken for mosquitoes, resembling 

 them somewhat superficially, but unlike mosquitoes, they are, with a 

 few exceptions, harmless to man. One curious and distinguishing 

 difference between them and mosquitoes is the fact that when resting 

 they usually lift their fore legs in the air, whereas mosquitoes when 

 resting generally have their hind legs raised. There are in ^H con- 



