548 MR. YOUATT S VETERINARY LECTURES. 
that the thorax is always full, whether in its state of expansion 
or contraction; always in close contact with its contents, it will 
be evident that the capacity of the chest is the measure of the 
bulk of its contents. Then as a circle is that figure which con¬ 
tains more than any other of equal girth or admeasurement, it 
would follow that a circular form of the chest is most advan¬ 
tageous. Not exactly so; for the contents of the chest are alter¬ 
nately expanding and contracting, and the parietes of the chest 
and the area of the chest must vary with this. The circular 
chest could not expand, for every change of form would be a 
diminution of capacity. 
Should approach to a circular Form in Cattle. —Then we will 
alter our proposition a little—that form of chest which approaches 
nearest to a circle, while it admits of sufficient expansion and 
contraction, is the best—certainly for some animals, and for all 
animals under peculiar circumstances, and with reference to the 
discharge of certain functions. This must be received as a fun¬ 
damental principle in the breeding of every animal that is valued 
for quickness of feeding or the accumulation of flesh and fat. 
It was the grand principle on which Mr. Bakewell proceeded, 
and on which all our improvements in the breeding of cattle were 
founded. Mr. Cline says, and truly, that “ the power to pre¬ 
pare the greatest quantity of nourishment from a given quantity 
of food depends principally on the magnitude of the lungs to 
which the organs of digestion” (and he might have added, all 
the organs of the frame) “are subservient.” Mr. Bakewell 
laboured hard to get rid of the flat-sidedness of many of our 
old breeds of cattle. He gave them considerably more breadth 
before, and when he failed in that, he gave them that filling out 
at the posterior part of the thorax, which the good judge of the 
points of cattle likes to see—that progressive and rapid breadth 
from the elbow backward which never failed to indicate a kindly 
feeder. 
In some Breeds of Horses .— The Heavy-Draught Horse .— 
The principle holds good with regard to some breeds of horses. 
We value the heavy draught-horse not only on account of his 
simple muscular power, but the weight which, by means of that 
power, he is able to throw into the collar. A light horse may be 
preferable for light draught, but we must oppose weight to weight 
when our loads are heavy. In the dray-horse we prize this 
circular chest, not only that he may be proportionably heavier 
before (to him no disadvantage, for the weight he has behind 
him will keep him from falling), but that, by means of the in¬ 
creased .capacity of his chest, he may obtain the bulk and size 
which best fit him for our service. But he would not do for 
