and gradually darkens, ultimately becoming almost black in color. 

 This contracted and hardened larva is what is known as the puparium, 

 which, except for its changed color, texture, and shape, preserves all 

 of the characteristics of the larva. From three to six weeks later the 

 perfect fly escapes by pushing off a sort of circular piece or cap at 

 one end of the puparium. The illustration (fig. 9) represents this 

 stage in the allied species, hovis. 



The establishment of the wandering habits of the larva in its early 

 stages and the fact of its entrance into the animal through the mouth 

 and esophagus, instead of the skin of the back, is l)ased on carefid 

 experiments and examinations conducted by Doctor Curtice, and is 

 apparentl}' now well established, though difl'ering so radically from llie 



Fig. 8. — Hypoderma Unealu: a, second stage of larva from liack; h and c, cnlar 

 d, ventral view of third stage with details of extremities at c and/; g, dorsal vie 

 enlargement of anal spiracles at 7;; j, the same, lateral view — natural size indie: 

 Insect Life) . 



gement of e 

 w of mature 

 ited 1)V side 



X t rem i ties; 

 larva with 

 lines (from 



views formerly held. The wandering lia])its of this larva are further 

 indicated by a number of well-authenticated cases of its occurrence 

 beneath the skin of the human subject. There it has usually exhib- 

 ited a similar wandering tendency, in one instance having covered a 

 distance of several yards before being removed. This ])articular 

 larva is represented in the accompanying illustration (fig. 10). Its 

 entrance into the human subject can be easily accoimted for by sup- 

 posing it to be taken with milk. 



In general appearance and size, the adult insect, roughly speaking, 

 is not unlike the common honeybee. It is about one-half an inch 

 long, the general color black, and is clothed with yellowish white 

 and reddish brown and black hairs. The margin of the head and 

 thorax and a band on the base of the abdomen are covered with long 

 whitish hairs. The upper surface of the head and thorax, and the 

 middle segments of the abdomen, together with the legs, are covered 



