278 OBSERVATIONS ON INSECTS. 



resembles a bee in general appearance, that persons 

 who are not entomologists constantly mistake them 

 for such, and call them drones. I observe that 

 almost all the individuals that come into houses in 

 this manner are, as in the case of gnats already 

 alluded to, females. 



ANTHOMYIA CANICULARIS. 



IN the spring of 1837, a physician at Cambridge 

 acquainted me with a case which had occurred to 

 him a short time previous in his practice in that 

 neighbourhood, in which large quantities of the 

 larvae of some dipterous insect were expelled from 

 the human intestines. Some of these were sub- 

 mitted to my inspection, and proved to be the larvae 

 of the Anthomyia canicularis of Meigen. The 

 patient was a clergyman, about seventy years of age. 

 The symptoms of which he complained, previously 

 to the first appearance of these larvae, were general 

 weakness, loss of appetite, and a disagreeable sensa- 

 tion about the epigastrium, which he described as a 

 tremulous motion. These symptoms commenced in 

 the spring of 1836, and it was not till the summer 

 and autumn of that year that the larvae were observed 

 in the motions. They then passed off in very large 

 quantities on different occasions, the discharge conti- 

 nuing at intervals for several months. According to 

 the patient's own statement, the chamber-vessel was 

 sometimes half-full of these animals ; at other times 

 they were mixed with the stools. He thinks that 

 altogether the quantity evacuated must have amount- 



