OF THE LARVA OF CORETHRA PLUMICORNIS. 



75 



curved teeth. Passing through this organ, we see an extremely 

 narrow oesophagus, which extends through the third segment. It is 

 composed of longitudinal muscles, and accompanied on either side 

 by a slender nerve. This oesophagus passes into a wide extremity 

 of the stomach. The stomach extends from the third segment, 

 tapering gradually to the ninth segment, when it is slightly enlarged, 

 and four ca3cal tubes are given off from it, two going as far as the 

 eleventh segment and two stopping short in the tenth. I cannot 

 speak positively of the office of these tubes, but I think they may 

 be biliary tubes, as sometimes when the larva is well fed they are 

 filled with a yellow secretion ; they have thick nucleated walls, with 

 granular structure. Passing from the juncture of these tubes, the 

 alimentary canal again becomes suddenly narrowed to a tube but 

 little wider than the oesophagus, and then as suddenly becomes 

 dilated to form what would be a rectal pouch, showing, however, no 

 evidence of rectal papillae ; the alimentary canal then tapers off 

 again and ends in an opening in the centre of the four finger-shaped 

 processes which help to form the tail. It is a very rare thing to 

 find anything approaching to the nature of solid food in this canal, 

 and in one larva which I examined we may find the explanation for 

 this — its pharynx was widely distended with small daphniaa and 

 cyprides, and the stomach was in active peristaltis, when after a time 

 it vomited the shells, and a violent jerk of the body scattered the 

 evidences of its meal. 



But now, approaching condensation of the integument partially 

 obscures the sight of the wondrous changes taking place within ; 

 even this obstacle to further observation is attended by much in- 

 terest, for we notice amoeboid corpuscles in active movement, gather- 

 ing together in groups in the endothelial lining of the outer shell 

 of the larva, and especially in the neighbourhood of the union 

 between the segments, and uniting by their borders form hexagonal 

 or polygonal cells, in which may often be seen brown particles which 

 may ultimately furnish the chitinous tissue of the future pupa. It 

 is this subsequent obscuration which will bar our progress in watch- 

 ing the further developmental changes, and it is to be regretted, 

 inasmuch as it would be of great interest to see from which tissues 

 the wings are formed. We can only hope that when this larva under- 

 goes its first moult and passes into the pupa, the integument may 

 be sufficiently transparent to enable us to record further develop- 

 ment. Gentlemen, I hope I am not wrong in presuming that what 



