566 The American Naturalist. [July, 
adhered to. "Thistype, in all cases, should represent the high- 
est development of characters that indicate the posession of 
the desired useful qualities. The form should be that which 
represents a special adaptation to the particular purpose in 
view. It is well known that the general form of animals is 
correlated with particular functions. The form of the roadster 
differs from that which is suited for heavy draft, and the type 
for rapid meat production is different from that giving the 
best results in the production of milk. 
The law of correlation has, however, a further application. 
There is not only an adaptation of the general form to the 
kind of work that can best be done, but the different organs 
of the body have correlated relations that are quite as signifi- 
eant. An excessive activity, or development of one organ, or 
set of organs, diminishes the activity or development of the 
system in other directions. That is tosay, the system has a 
capacity for utilizing a certain amount of energy, and if it is 
largely expended in one direction there is less to be expended 
for other purposes. If the tendeney to lay on fat predominates, 
the milk producing functions must suffer a corresponding 
diminution, and severe muscular work will diminish the ten- 
dency to lay on fat, or produce milk. 
To give permanency and uniformity to the ideal type that 
has been adopted, selections for breeding must be strictly con- 
fined to animals having the desired characters, within the 
limits of a distinct breed, or of a single family of a distinct 
breed. This is in effect establishing, or fixing, family charac- 
ters in the particular breed. The constitution or physical 
stamina of the family type should not be lost sight of in 
attempts to secure other desirable characters, as on it will 
depend the efficiency and profitable exercise of the special 
functions that have been cultivated and fixed as family char- 
acters. 
All coarseness should be avoided. Improvements in all 
breeds have been made by securing a greater refinement of the 
system, or in diminishing the proportion of coarse parts. 
Large bones, with apparent good reason, have been looked 
upon as an indication of imperfect nutrition, and as a general 
