140 



THE AMERICAN ENTOMOLOGIST. 



lai-vai had been swallowed alive, along with 

 such vegetable food as had been introduced in 

 the ordinary course of nature into the stomach; 

 the other by our friend Dr. Wilson, of Quincy, 

 who expresses his belief that a few larvas had 

 been introduced through the mouth, and that 

 then after getting into the alimentary canal had 

 increased and multiplied there. We must crave 

 leave to differ from both these gentlemen. In 

 the first place, we can scarcely understand how 

 larva3 of such considerable size and of so soft a 

 consistence could escape being crushed more or 

 less by the human teeth during the process of 

 mastication; and in the second place, although 

 in the whole Class of Insects there is a single 

 most remarkable and exceptional genus {Mias- 

 ior), belonging to the Gall-gnat (Cecidomyia) 

 Family, which is known to propagate in tlie 

 larva stale, yet this is the exception and not tlie 

 rule. For out of sibout a hundred thousand dis- 

 tinct genera of Insects which exist in the whole 

 world, no other genus,- so far as the records 

 show, has the reproductive faculty developed 

 until il reaches the mature or Perfect State. 

 For thcpc rciisons, we incline to believe that 

 larvae dischai-ged from the human body, in the 

 manner recited above, nuist all of them have 

 been originally introdnccd there in the egg 

 state, and after reaching the stomach must have 

 hatched out and fed upon the food taken from 

 time to time into the stomach. No doubt, the 

 great majority of eggs that are swallowed in 

 this manner, even if they escape being crushed 

 by the teeth, perish in the healthy human body, 

 either before, or shortly after batching out, 

 owing to the unnatural conditions to which 

 they are necessarily subjected there, both as 

 regards temperature, and want of air, and the 

 presence of tliat powerful chemical agent — the 

 gastric jnice. But in a diseased and abnormal 

 body, it may, and doubtless does, occasionally 

 happen, that tlie average temperature of the 

 stomach is reduced much below the normal 

 point, or that large quantities of gaseous matter 

 containing oxygen are formed there, or that an 

 insufficient supply of gastric juice is secreted 

 there; and in such instances as these, the eggs 

 may probably hatch out, and the young larvse 

 may, without any material injury to their health, 

 grow and reach maturity. 



It is not a very plea=ant thing to have a 

 stomach full of lively living maggots. Still, it 

 should be borne in mind that, although such 

 maggots may temporarily derange the health, 

 there is no reason to suppose that thej- can ever 

 cause death. Moreover, when more or less 

 matured, such insects will always pass away, 



either dead or alive, by the ordinary modes in 

 which such offensive matter is ejected from the 

 human system ; for it is utterly impossible that 

 they can ever after developing into the perfect 

 winged state, propagate their species among 

 the semi-fluid contents of the alimentary canal. 

 Consequently, unless a fresh supply of eggs is 

 introduced into the stomach, the original gene- 

 ration of maggots will soon disappear; for with 

 almost all the different larvoe of Two-winged 

 Flies that subsist upon decaying matter, whether 

 animal or vegelable, the larval period is com- 

 paratively quite short — say two or three weeks, 

 or at most a month. 



The nature of tlio substances upon which the 

 larvffi usually dis^charged from the human body 

 naturally i'eed — that is, decaying animal and 

 especially decaying vegetable matter — indicates 

 at once the manner in which the eggs that 

 produce these larvie gain admission into the 

 stomach. We have already stated that we have 

 bred great numbers of a small species of Flat-fly 

 from rotlcn plums; and we may add here tliat 

 the plums fi'om which wo bi-ed the Fly were 

 most of thom only partially unsound when they 

 were gathei'cd and placed in the Breeding-vase, 

 and that after they were placed there no living 

 insect could possibly have gained access to them 

 in Older to lay its eggs upon them. Conse- 

 quently, a good many of the eggs which after- 

 wards produced the Winged Flat-flies must in 

 all probability have been deposited in the open 

 air upon plums that were only partially un- 

 sound — say with only a third or a fourth part 

 of their flesh discolored and soft. Such fruit 

 would be greedily devoured by many children, 

 and by some grown persons who do not know 

 any better. But we have ascertained by a some- 

 what extensive experience in breeding insects, 

 that fruit which is either wholly or partially 

 decayed almost invariably contains great num- 

 bers of the eggs of different Two-winged Flies, 

 belonging to many different genera (Sciara, 

 Scato2}se, DrosopMla, Hovialomyia, and Mus- 

 ed) , the larvas of which naturally feed upon such 

 substances. When, therefore, such decayed fruit 

 is introduced into the human stomach, these 

 eggs, being excessively minute, will doubtless 

 many of them pass uninjured into the body; 

 and if that body happens to be in a diseased and 

 unhealthy state, they will probably hatch out 

 and develop into a whole generation of larvfe. 



In ninety-nine cases out of a hundred, per- 

 haps, these intestinal larvre will be voided with- 

 out being noticed by any one ; and the functional 

 distiirbance which they have caused will be 

 attributed to cholera morbus, or summer com- 



