98 ANIMAL PARASITES. 



of tobacco is better. But if we are clumsy in seizing the ani- 

 mals with the forceps, they rapidly creep back. After their 

 removal, the cavities which they have made and the excrescences 

 in their neighbourhood soon heal. 



b. The common Flesh-fly = Sarcophaga = Musca carnaria. 



This also occurs sometimes in external wounds or ulcers 

 in the human body, as it lays its eggs in which the larvae 

 are usually ready formed, or its larvae, which sometimes leave 

 the egg even within the body of the mother, on every animal 

 structure or nutritive material derived from the animal kingdom 

 subject to the laws of decomposition. In the latter case the 

 young immediately begin to eat. In the heat of summer 

 and in hot climates the larvae easily get into badly managed 

 putrid, and open wounds ; nay, even the short time occupied in 

 dressing is sufficient to enable the fly to deposit her brood 

 in them, if particular care be not taken. Attracted by the 

 srnell, this fly, as well as the preceding, deposits its eggs and 

 larvae in the vagina of little girls or women when they lie naked 

 in hot summer days upon dirty clothes, or when they have a 

 discharge from the vagina. In malignant inflammations of the 

 eyes, the larvae of this and the preceding fly even nestle under 

 the eyelids, and in Egypt, for example, produce a very serious 

 addition to the effects of smallpox upon the cornea, as, accord- 

 ing to Pruner, in such cases a perforation of the cornea usually 

 takes place. 



c. The larvae of Musca domestica and stabulans. 



These larvae sometimes occur in sores, or in the vagina of 

 girls. Thus, for instance, I have seen a nest of them in the 

 vaginal orifice of a little girl in the summer, and removed them 

 by injections of chamomile. The eggs of the common house- 

 fly, according to Leuckart, are only a little smaller than those 

 of the bluebottle, and very similar to them in form. They are, 

 however, more pointed towards the anterior pole, and have a thicker 

 chorion, which becomes as much as ~" in thickness at the poles. 

 The chorion has wide pits and facets. At the poles the pits 



