344 Mr. Newport on the Natural History 



the larva does not readily quit them. I kft four or five specimens during the 

 night, on hairs, beneath the microscope : three of the larvae were attached to 

 the hairs. In the morning two of them had escaped, and one only was still 

 clinging to a hair ; so that we may fairly conclude that they sometimes wan- 

 der in search of the object of their parasitism. 



Internal Anatomy of Stylops. 



I have succeeded in tracing the alimentary canal of the larva throughout 

 its whole course, and I believe am enabled somewhat to extend the observa- 

 tions of Dr. Siebold on this part of its anatomy. Dr. Siebold describes the 

 larvae of the species he examined, Stylops Mjslittoe and Xenos Rossii and sphe- 

 cidarum, as having a simple csecal intestine, but no anal outlet. My own 

 observations lead me to a different conclusion. The alimentary canal com- 

 mences in a narrow oesophagus, which is gradually enlarged as it passes back- 

 wards through the thoracic segments, until it has reached the first abdominal 

 one, where it is dilated into a kind of crop. An abrupt constriction, the car- 

 diac valve, separates this from the continuation of the canal, the true stomach, 

 or chylific ventricle. This part is considerably enlarged, and commences 

 within the posterior margin of the first abdominal segment, the fifth of the 

 whole body, as in other insects. The canal then pursues nearly a direct 

 course as far as the ninth segment, the fourth of the abdomen, in which it is 

 folded on itself and again turns forward, that portion which passes forward 

 being on the under surface. This gives to the anterior, the uppermost portion 

 of the chylific ventricle, an appearance of caecal termination. I suspect it was 

 this appearance which led that distinguished observer Dr. Siebold to describe 

 the canal as simple and merely caecal. When the canal has thus passed for- 

 wards for a short distance, it is again folded backwards in the next segment, 

 and is then indistinctly traced onwards until seen in the thirteenth segment 

 as the rectum. I have no doubt that a true anal outlet exists to the canal at 

 this period of the larva state, although it is not improbable it may become 

 closed at a subsequent one, when the parasite is included in the abdomen of 

 the bee larva. I have indeed noticed what seems to be a demonstration that 

 the canal in the young larva is not closed. While observing a larva that was 

 moving along on a plate of glass, a little faecal mass seemed to be voided by 



