24 
THE OX AND ITS KINDRED 
massiveness of the vertebras. The tendency to the 
assumption of a spout-like form in the odontoid 
process of the axis vertebra of the horse is a second 
instance of that parallelism in development between 
the members of the equine family and the typical 
ruminants which is still more pronounced in the 
skeleton of the feet. 
A third instance of such parallelism is afforded by 
the cup-and-ball articulations of the five vertebrae of 
the neck situated behind the axis in the Pecora and 
the members of the horse family, this structure 
being likewise designed (I use the word advisedly) 
to confer additional strength on the neck. In both 
the ox and the horse the cup is situated at the hind 
end and the ball at the front of each of these vertebrae. 
Other characteristic features of the ruminant 
skeleton are to be found in the bones of the lower 
part of the legs, where specialisation has been carried 
to the greatest extent in the hind-limbs. In the case 
of the fore-legs the ulna, or larger bone, has become 
more or less rudimentary and incomplete inferiorly, 
while its upper end is firmly welded to the upper 
portion of the radius, or (typically) smaller bone, 
which is now the chief constituent element of this 
portion of the limb. This modification, which is also 
paralleled in the horse, is designed to confer strength 
combined with lightness to the leg. In the hind- 
limb the fibula, or smaller bone of the lower segment 
of the leg, is represented only by its two extremities, 
of which the upper forms a small pointed style welded 
above to the corresponding end of the tibia, or 
larger bone, while the lower extremity is represented 
by a detached nodular bone lying on the outer side 
of the lower end of the tibia. In the horse this 
