220 The Journal of Heredity 
MCKINNEY, A TROTTING STALLION 
McKinney was a registered trotting horse No. 8818, seven generations from the pure Arab Grand 
Bashaw. 
vertebra and lateral processes of the first lumbar vertebra developed into ribs. 
bone. With a saddle on, I believe he 
could have carried weight and endured 
long distance. Whether such cases 
of atavism are common in the trotting 
horse family I do not know, but in those 
particular cases they ought to be able 
to do the work of the Arab. I believe 
they are very rare. ‘‘Nancy Hanks’”’ 
was apparently of this build. 
WHY THE ARAB CAN ENDURE LONG TESTS 
What do these facts mean to the 
breeders of horses? Refer to Figures 
20 and 23, and one other specimen in the 
Museum of Natural History. These 
are three examples of a short back 
mare being bred to a stallion with 24 
vertebrae and the product in each case 
having the short back of the dam. 
This seems to indicate the dominance 
of the dam over the anatomy of the 
foal. 
His skeleton (in the Museum of Natural History, New York) shows the 18th dorsal 
(Fig. 22.) 
I think most breeders believe that 
proportion and anatomy have a rela- 
tion to speed performance, and if it is 
so, the above dominance of the dam is 
borne out by the fact that the success- 
ful breeders have paid especial atten- 
tion to the quality of the dams, and 
those who have not shown such good 
judgment have not been successful. 
Just why the Arab horse is the best 
weight carrier among the equines is 
simply because the bridge of his back 
is shorter between supports and there- 
fore stronger. 
The other anatomical differences 
mentioned in the first part of this 
article enable him to carry relatively 
more food for a long journey and 
therefore he can endure  privation 
better than a horse who has less ‘‘dinner 
basket’ capacity. Consequently it is 
quite natural for an Arab Horse to win 
