- 52 - 
no pain at any time, but it irritated her when walking, as it felt 
as if she had a foreign body in her shoe. A physician opened 
the "papilla" a month ago, prooing down the "canal" and finally 
took from it an adult wood tick (the spotted fever type), which 
was quite hard and completely mummified. With the cause of "the 
lump" thus removed, the physician deemed further operation un- 
necessary. A week ago the same student told me that the lump 
was rapidly disappearing and scarcely noticeable when she walked. 
The time of infection is of interest. The girl could not give 
me an exact date, but she felt that the parasite had attached 
itself during April or May last year (19 23) since at that time 
she had gone on frequent picnics to the woods around Moscow. 
Since then she had not Deen into the woods. Indeed, she had 
first noticed the formation of a small lump late last summer, but 
had not considered it of sufficient importance to consult a physi- 
cian. Evidently the tick had fastened to her heel and bored its 
way into the epidermis. Since the heel is much in use, there was 
a protective hypertrophy of epidermal and subcutaneous tissue to 
cut off or surround the parasite, thus causing "a lump". Death 
of the parasite, I imagine, came from the sweat and lack of oxygen. 
After that the parasite was passive, but the tissue still con- 
tinued its attempt to isolate the foreign body. The interesting 
feature of the case is the unusual point of attack; the remainder 
is merely a repetition of the usual defensive methods of the body 
against foreign bodies. Students come to me often enough to tell 
me of wood-tick bites. But these occur most frequently below the 
knee, in the groin, in the axilla, but especially just below the 
margin of the shoulder-blade. I have also taken a tick or two 
from the heads of a boy and a girl. 
CATTLE 
CANYON HORSE-VLY ( Tab anus rubes cens Bellardi) 
Texas D. C. P arm an (April 21): One specimen of the canyon horse-fly 
has been observed at the laboratory on April 16- This is a very 
early date for appearance and is the earliest on record for appear- 
ance at the laboratory. None were observed in the canyons on 
April 19. 
SCKEWORF ( Chrysomya macellaria T?ab.) 
Texas D. C. P arm an (April 21): The screwworm fly is increasing in 
numbers and the winter blow-fly is diminishing rapidly, about 
50-50 on the first of this month and is about 85 per cent se*?w- 
worm flies and 15 per cent Phormia regina on April 21. Several 
cases of worms have appeared on ranches and it will probably be 
a year of many cases of worms as the adults have appeared in 
greater numcers at an earlier date than no real. 
