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THE AMERICAN MUSEUM JOURNAL 



infant paralysis may spread by direct contact between human beings or 

 in other ways than by fly bites. On the other hand it seems certain that 

 the biting stable fly is one means by which this disease is conveyed; and the 

 seasonal and geographical prevalence of the epidemics makes it seem prob- 

 able that this is the usual and most important means. 



The Stomoxys calcitrans like the house fly or filth fly (Musca domestica) 

 is a two-winged fly 

 of the family Musci- 

 dse. It closely re- 

 sembles the house 

 fly in general form 

 and size and may 

 easily be mistaken 

 for it by the casual 

 observer. It differs 

 from the house fly 

 in one very impor- 

 tant respect how- 

 ever, in the posses- 

 sion of a sharp biting 

 proboscis instead of 

 the soft tongue-like 

 mouth parts with 

 which the house fly 

 absorbs its food. 

 This proboscis of 

 the Stomoxys may be 

 seen projecting for- 

 ward as a fine black 

 beak when the insect 

 is at rest. Another 

 important difference 

 lies in the venation 

 of the wings, the 

 third of the long 

 veins being bent at 

 a less sharp angle in 

 the Stomoxys than in the house fly. Two additional points of difference 

 between the house fly and the stable fly are brought out in Mr. Matausch's 

 original drawing reproduced herewith: that the posterior edge of the 

 compound eye as seen in side view is concave in Stomoxys calcitrans and 

 practically straight in Musca domestica; and the antennae of Stomoxys 

 calcitrans are clothed with hairs on the upper side only while those of Musca 

 domestica have hairs both above and below. 



Mr. Ignaz Matausch, preparator, who has recently completed 

 a marvelous piece of technical work in the shape of an enlarged 

 model of the common house fly. It represents a magnification of 

 64,000 diameters, required one year for its construction and is the 

 most accurate representation of this insect in existence 



