DIRECT INJURIES CAUSED BY INSECTS. 139 



the sight more horrid a ." — A medical friend of mine, at 

 Ipswich, gave me this winter an apode larva voided by 

 a person of that place with his urine, which I now preserve 

 in spirits and can show you when you visit me. It appears 

 to me to belong to the Diptera order, yet not to the fly 

 tribe (Muscidce), but rather to the Tijpulidce, with which 

 however it does not seem to agree so entirely as to take 

 away all doubt. It is a very singular larva, and I can 

 find none in any author that I have had an opportunity 

 of consulting which at all resembles it. That you may 

 know it, should you chance to meet with it, I shall here 

 describe it. Body, three fourths of an inch in length, and 

 about a line in breadth ; opaque, of a pale yellow colour ; 

 cylindrical, tapering somewhat at each extremity; con- 

 sisting of twenty articulations without the head: Head 

 reddish brown, heartshaped, much smaller than the fol- 

 lowing joint; armed with two unguiform mandibles; with 

 a biarticulate palpus attached exteriorly to the base of each. 

 These mandibles appear to be moved by a narrow black 

 central tendon under the dorsal skin terminating a little 

 beyond the base of the first segment; besides this, there 

 are four others, two on each side of it, the outer ones di- 

 verging, much slenderer, and very short. The last or anal 

 joint of the body very minute; exerting two short, filiform 

 horns, or rather respiratory organs. I could discover, in 

 this animal, no respiratory plates, such as are found in 

 the larvse of Muscidae, nor were the tracheae visible. 

 When given to me, it was alive and extremely active, 

 writhing itself into various contortions with great agility. 

 It moved, like other dipterous larvae, by means of its man- 



a In passing through this parish last spring, I inquired of the mail- 

 coachman whether he had heard of this story; and he said the fact 

 was well known, 



