336 
PARASITIC DERMITIS IN A DOG. 
Mr. Austin says “ that although the disease had existed so 
long, and the itching was always very considerable, still, when 
the animal was brought under my care, no eruption was visible. 
The owner despaired of a cure being effected. On making a 
close examination, I discovered a number of little animals, 
unlike any I have ever seen before, upon nearly every part 
of the body. I have succeeded in getting some of these alive, 
mixed, however, with much dirt and scales of cuticle. I send 
them by a friend, and hope that they will reach you before 
they are dead or dried up.’ 5 
We regret that more than a month elapsed before the small 
jar, in which these parasites were put, came to hand, and we 
despaired therefore of finding any of them alive. To our sur- 
prise, however, we found three or four still living among the 
mass of dirt. A slight examination with the naked eye was 
sufficient to show that these were the larvae of some insect, 
and the microscope at once revealed them to be the larvae of 
the dog-flea. Further search showed that there were nume- 
rous dead larvae and exuviae in the mass, and therefore, to 
facilitate our future examination, the whole was placed in a 
phial with some diluted spirit, that the organisms might be 
freed from the dirt and be the more readily selected after 
their imbibition of the fluid. By this means we have obtained 
specimens which render the history of the dog-flea perfect 
and complete. Thus, we have in our possession ova, show- 
ing more or less perfectly the formation of larvae within 
them; ova-cases, from which the larvae had escaped; larvae 
in different stages of their growth ; exuviae, as cast off from 
time to time from the growing larvae; pup^e, in their various 
stages of change into the perfect insect, and insects them- 
selves, just brought into active life. 
This case we consider to be both interesting and instruc- 
tive, and no less so to the veterinary pathologist than to the 
naturalist, as showing that all the transformations of this in- 
sect can be completed upon the body of an animal, and as 
such, the disease induced by fleas would be persistent. 
