CIRCULAR-SEAMED FLIES 



3029 



quently selected as objects of attack on the part of these flies. In one case the eggs 

 of a greenbottle fly were laid on a toad's back, and the larvae upon hatching 

 migrated into its eyes. In other cases the laying of the eggs and migration of the 

 larvae have not been actually observed, but toads have been found with their nostrils 

 infested with maggots; and it is possible that the latter may have effected an entry 

 from the outside, as described above. Mr. Guthrie, who noticed the occurrence of 

 the larvae of a bluebottle {Calliphora} in the nostrils of toads, writes that "it is 

 probable that the number of toads is largely kept under by those means. In 1872 

 toads were remarkably plentiful in the neighborhood of Tenby, South Wales, and I 

 noticed that the disease was very prevalent among them. In the following year 

 scarcely any could be found, and I saw none diseased." Cases are also on record 

 of the death of lizards from maggots of blowflies, which testify to the extraordinary 

 vitality of the latter. In one instance a gecko fed on bluebottles was found to have 



GROUP OK FL.IES AND THEIR GRUBS. 



i. Blowfly; 2. Eggs; 3. I,arvse; 4. Pupa; 5. Newly-born larva of gray flesh fly; 6, Gray flesh fly; 7. Adult larva 

 of the same; 8. House fly and larva; 9. Sharp-mouthed fly; 10. Head of house fly; u. Foot of gray flesh 

 fly; 12. Carcass of house fly killed by fungus growth, do, n, enlarged; the other natural size.) 



the whole abdominal region greatly distended. It soon afterward died, and on 

 dissection its intestines, lungs, and liver were found to be almost entirely destroyed 

 by maggots, whose presence was naturally attributed to eggs from gravid female 

 bluebottles, which had been swallowed as food. In another case, some lizards fed 

 on the living maggots of the bluebottle died in consequence of the attacks on their 

 internal organs by their intended food. Far more important are the cases of infec- 

 tion of human beings; the resulting sickness, which often entails great suffering^ 

 and may end in death, being known as myiasis. 



The sharp-mouthed fly (Stomoxys calcitrans}, represented in' 9 of the figure orr. 

 p. 3028, closely resembles the house fly in size, shape, and coloring, but may be? 

 recognized by its sharp, horizontally projecting proboscis, and also by the flagellumi 

 of the antennae being hairy upon one side only. It is less often seen in houses- 

 than the house fly, although occasionally paying them a visit, especially if there be 



