[18] 234 



minute hooks. There are two sets of spiracles (amphipneustic). The 

 pair at the hinder end of the body is shortly bilobed, the anterior 

 pair, in line with the mouth, is fan shaped and eight-lobed. An 

 interesting fact is that in a number of cases the larva, when found, was 

 holding on firmly to one of the larger tracheal trunks of the host, by 

 means of its hooks. Unfortunately so far the exact relations to the 

 tracheal system have not been made out, and the fact just recorded may 

 have no particular significance. But it may be recalled here how, in the 

 case of Ugimyia sericaria, a Tachinid parasite of the silkworm caterpillar in 

 Japan, the maggot early " enters the tracheal system, boring into a tube near 

 a stigmatic orifice of the silkworm, where it forms a chamber for itself by 

 biting portions of the tissues and fastening them together with saliva. In 

 this it completes its growth, feeding on the interior of the silkworm with 

 its anterior part, and breathing through the stigmatic orifice of its host " 

 (Sasaki : quoted from Sharp, Camb. Nat. Hist.). The maggot in the Tipula 

 larva was never found near the stigmata, which are terminal, but was 

 always situated in the middle region of the body. It may also be mentioned 

 here that in several cases two maggots were found. 



The hook apparatus of the maggot is moderately complex and may be 

 briefly described. There is a large basal plate bearing a pair of wings or 

 lateral plates with rounded posterior margins. In front of the median plate 

 lies the hook apparatus proper. This consists of a ladder-like arrangement 

 of cross bars bearing at its anterior end a pair of hooks. These hooks 

 have a pair of rounded extensions at their base directed both forward 

 and backward. 



{Issued separately, 22nd January 1912.) 



(From Froe. Royal Physical Society, Edinburgh, vol. xviii., pt. 4, no. xxiv.; the original 

 pagination is without parenthesis.) 



