Insects, 



6171 



doubt, will seem a strange localily, and surprise the many who are 

 unacquainted with the fact ; but Bracy Clark remarks of the sheep bot 

 that "I have mostly found them in the horns* and frontal sinuses; 

 though 1 have remarked that the membranes lining these cavities were 

 hardly at all inflamed, while those of the maxillary sinuses were highly 

 so. From this I am led to suspect that they inhabit the maxillary 

 sinuses, and crawl, on the death of the animal, into these situations in 

 the horns and frontal sinuses and he refers to a case recorded in the 

 first volume of the ' Medical Communications,' in which " insects were 

 removed from the antrum maxillare of a woman, and are evidently, as 

 Dr. Latham has supposed, the larvae of the CEstrus Bovis." How so, 

 this being a subcutaneous larva, infesting the back and sides of horned 

 cattle, and not even horses ? Which alone is also an exceedingly 

 strong argument against its being the fearful tzetze of Africa, with 

 which Mr. Clark now^ alleges its identity ! 



The French naturalists divide the QEstrida3 into " cuticoles," cavi- 

 coles" and gastricoles according as the larva inhabits beneath the 

 skin, the facial cavities, or some part of the alimentary canal of mam- 

 miferous animals ; and it is not likely that the same kind of bot would 

 be found in two of those situations. But the same species of gadtly 

 infests different sorts of quadrupeds in some instances, as the CEstrus 

 nasalis of LinnaBus, which, according to Macquart, is found (/. e. in its 

 maggot state) in the gullet not only of the equine animals, but of the 

 stag and goat, — thus both in ruminants and non-ruminants! Again, 

 the CE. Pecorum finds its way into the intestines of ruminating cattle ; 

 and at least four species inhabit different parts of the alimentary canal 

 of the horse. Other gadflies produce bots which subsist beneath the 

 thick hide of the camel, and even of the African rhinoceroses and 

 elephant; and there are "brize flies" also which pierce the hides of 

 those huge quadrupeds (according to Bruce and others), as mosquitos 

 do the human skin ; but the Carnivora, so far as known, are exempt 

 from Q^strideous parasites. Then we have African birds (the genus 

 Buphaga) which seem specially ordained to rid the beasts of their 

 subcutaneous maggots, and are otherwise useful to them as sentinels 

 to warn them of the approach of man or other foes; and it is curious 

 that the common Cape "ox-picker" {B. africana) has its beak naturally 

 tipped with crimson, looking as if it had been di])ped in blood; that 

 of Abyssinia, &c. (B. erythrorhyncha) has the beak wholly crimson. 



The CEstrus nasalis before adverted to is designated Q]. veterinus by 



^ The interior of the cavity of the bone which supports ihe horn. 



