INSECTS AND DISEASE 83 



Another series <>t" exhibits deals with the transmission of disease by in- 



Beets, notably by the fly and fl«a. The most striking feature 



insects of these is a model of the fly, a little over a foot in length, and 



Disease having the bulk of 64,000 flies. This, the finest model of the 



kind ever made, was prepared by [gnaz Matausch from his 



original studies, and required nearly a year of constant, exacting labor. 



The egg, larva and pupa of the insect are also shown modeled on the 

 same scale. 



Models in the wall case deal with the life history of the fly showing its 

 various Stages in their natural size and actual habitat and illustrate the large 

 numbers of flies which may breed in a single pound of manure and the 

 enormous progeny which may spring from a single pair and their descendants 

 during the breeding season. 



The deadly work of the fly in carrying typhoid fever is illustrated by 



a representation of two companies of soldiers, showing the 



Z. e , . , comparative mortality from flies and bullets during the 



Typhoid _ V , . ~ P , , 



pj Spanish-American war. One company confronted by a 



cannon, suffers the loss of one man wounded; another facing 



a tube of typhoid germs — distributed by flies — has one dead and thirteen 



in the hospital. 



Wall drawings near by show how the fly may carry typhoid bacilli on its 

 foot, with the number of bacteria found on flies in sanitary and unsanitary 

 surroundings; and illustrate the allied species, the stable fly, which it is 

 thought may carry infant paralysis and other diseases. 



Nearby are two models showing unsanitary and sanitary conditions 

 on a small farm. In one, pools of stagnant water and uncovered manure 

 heaps and general uncleanliness favor the breeding of mosquitoes and flies, 

 while the open doors and windows give these insects free access to the house. 

 In the other, the swampy land is drained and cultivated, the windows 

 screened, the shallow dug well replaced by a driven well; the conditions 

 are sanitary and health and prosperity replace sickness and poverty. 



Various types of traps for larvae and adult flies are shown with models 

 illustrating how fly breeding may be prevented and how human wastes may 

 be protected from their access. 



The relation of the flea and the rat to the terrible disease bubonic plague 



is illustrated in considerable detail. Wall charts illustrate 



* -r. f a • the spread of the great historic epidemics of this disease and 

 and Bubonic * T , , , , 



Plague reproductions of sixteenth and seventeenth century drawings 



show with what terror the Black Death was regarded in 



pre-scientific days. The chief carrier of the disease, the flea, is shown in 



a remarkable model 120 times the length of the actual insect and having 



the bulk of 1,728,000 fleas, prepared by Ignaz Matausch. 



Specimens of some of the principal animals which harbor the plague germ 



and serve as reservoirs from which it is carried by the flea to man (the black, 



