378 
ON ANIMAL PKRSPIRATION. 
scope, shews no trace of organization. The acari lay their eggs 
in little passages which they form under the skin. The young 
acari are produced from the eggs while in or under the skin, but 
it is impossible accurately to determine at what period after im¬ 
pregnation the egg is protruded and the incubation completed ; 
all we can do is to notice as early as possible the time that inter¬ 
venes between the entrance of a pregnant acarus under the 
sound skin and the appearance of young acari near the same 
place, and this, according to my observation, is generally from 
seven to nine days. 
When the acari first appear, they are scarcely one-third of 
their complete size. They grow however very quickly, and reach 
their full size in three or four davs. 
%/ 
Many writers have stated that the young acari change their 
skins once or twice. I will not pretend totally to deny this fact ; 
but I have never observed it, and it would be very difficult to 
prove either the truth or the falsehood of it. 
The young mites are exceedingly lively, and, in spite of their 
short legs, can run in the space of a minute over two inches of 
ground, whereas an old mite would only traverse an inch and a 
half in the same time. In walking they move their fore-feet in 
this order:—the outer fore foot on one side moves forward with 
the inner fore foot of the other side; and so on alternately. The 
hinder feet are very often only dragged along, and when they 
are brought into use at all it is only that pair which is furnished 
with suckers that move. 
The power of retaining life in this insect is even greater than 
that of the acari found in the scab in sheep. 
[To be continued.] 
ON ANIMAL PERSPIRATION. 
By I. J. H. 
Dear Sir,—As a subscriber to and a reader of your very 
valuable journal. The Veterinarian, I feel it my duty to 
contribute my mite for the perusal of the profession. 
An idea has lately struck me regarding “ animal perspiration,’^ 
and I am not aware that similar notions have been published by 
any one else. 
It has generally been thought that perspiration was a mere 
eliminating process of nature—a channel by which that power 
freed the system from those matters that were not only dispen¬ 
sable, but injurious to the well-working of the animal economy. 
