INDIVIDUAL VARIATION IN EQUUS ASINUS. 717* 
slaughtered cattle. No reflection could be more condemna¬ 
tory of their system. In place of a vigorous plan of extinc¬ 
tion founded on an intimate knowledge of the plague, and 
which bars all channels for its further diffusion, while the 
infection that is already in existence is being remorselessly 
stamped out , they adopt measures that are defective at every 
step, and while they restrict the pestilence at one point, they 
actually favour its spread to other parts of their territory and 
that of their neighbours. They cut down a few shoots that 
have already grown up into plants, but pay no attention to the 
incessant sowing of the same noxious seed going on all around 
them. They save a few thousand dollars to the treasuries of 
their respective States, but in doing so they are perpetuating the 
lung plague on the Continent at a present cost of 2,000,000 
dollars per annum to the nation, and they are every day en¬ 
dangering the spread of the plague to our Southern and Western 
cattle ranges at a prospective loss of 60,000,000 dollars per 
annum. An economy which puts men who are unacquainted with 
a plague in charge of the measures to be carried out for its exter¬ 
mination is the most reprehensible misappropriation of public 
money, since it leads the people to believe that ail necessary 
precautions are being taken, while in fact it is but maintaining 
a heavy expense with no adequate result. 
[To be co?itinued.) 
PRELIMINARY NOTES ON INDIVIDUAL VARIATION IN 
EQUUS ASINUS* 
By John Henri Steel, M.R.C.V.S., E.Z.S., Demonstrator of Anatomy 
at the Royal Veterinary College. 
The remarkable uniformity in external characteristics which 
ages of neglect and degradation have conferred upon the Ass of 
this country contrasts so forcibly with the amount of variation 
presented by certain of our domesticated animals that some have 
based upon it conclusions of a general nature tending to the 
admission of essential differences between the effects of natural 
selection and those resulting from artificial influences. Tor 
proof that these views are untenable we need simple refer to the 
fact that on the Continent, in the East, and even through quite 
recent artificial selection in America external variation in the Ass 
is very marked. With regard to modification of internal struc¬ 
tures, we believed the following are worthy of note as the 
From the Proceedings of the Zoological Society of London. 
49 
LI 11. 
