1930 ] 
Development of Dermatobia hominis 
329 
larva was placed on my arm it was completely out of sight 
in the skin and could not be seen even with the aid of a lens. 
There was absolutely no sensation caused by the entrance 
of this larva until after the first thirty minutes. Then, as 
the posterior end was being drawn inside, a sharp pricking, 
which lasted for about two minutes, was experienced. 
• The second larva was much slower in effecting an 
entrance and required an hour and thirty-five minutes to 
bury itself completely in the skin. At the end of an hour 
approximately half of the anterior end was inside. At 
this time I rolled down my shirt sleeve and put on my 
coat to determine if the rubbing of clothing would loosen 
the larva or have any apparent effect upon its entrance. 
After spending about thirty minutes in walking about and 
in doing some work in the laboratory which necessitated 
using my arm rather actively, I removed my coat and in- 
spected the larva. At this time it was all buried in the 
skin with the exception of the tip of the posterior end, 
and five minutes later that also was inside. 
During the night following the entrance of these two 
larvae into my skin a marked itching and pricking sensa- 
tion at the sites of their location was experenced at inter- 
vals. Although this did not last more than half a minute 
at each time it occurred, it was sharp enough to awaken 
me several times during the night. 
October 10. Fourteen hours after the entrance of the 
larvae it would have been nearly impossible to locate them. 
Since I had ringed the sites with ink, however, and thus 
knew their exact situations, they could with the aid of a 
lens be detected as pinpoint raised areas which were slightly 
reddish. After twenty-four hours they were visible to the 
naked eye as slightly elevated tiny red dots. When viewed 
closely with the lens the tiny posterior ends of the larvae 
could be detected slowing moving up and down in a pump- 
ing movement and forcing out minute quantities of fluid. 
October 11. This evening a sharp itching was felt at 
two small pimples which were at first thought to be caused 
by mosquito bites. One of these was located at the mid- 
ulnar margin of my right arm, approximately four and a 
half inches from the wrist joint. The other was on the 
internal surface of my right thigh about midway between 
