EVIDENCES FROM PALAEONTOLOGY 73 
diagram by Marsh, and in this (Fig. 2) the reader may trace upward 
from Orohippus to Equus the steady changes in fore and hind feet, 
bones of the forearm, bones of the lower leg, and the grinding teeth 
of upper and lower jaws. 
So definitely and clearly has the horse pedigree been worked out 
that, according to Dendy, “the palaeontological evidence amounts to 
a clear demonstration of the evolution of the horse from a fivé-toed 
ancestor along the lines indicated above.” 
For a long time the palaeontological series of the horse was un- 
rivaled by other vertebrate types, but now we have almost equally 
complete series for several other modern types, notably the camels. 
and the elephants. We shall present herewith accounts of the pedi- 
gree of the camels by Professor Scott, and that of the elephants by 
Professor Shull. And, to conclude the vertebrate pedigrees, we shall 
present in the next chapter that of man as given by Professor Lull. 
In extenuation of the use of vertebrate material to the exclusion 
of invertebrate, the present writer has only this to offer, that verte- 
brate material is more intelligible to the non-biological reader and is 
more in his own field of knowledge and interest.—Ep.] 
PEDIGREE OF THE CAMELS’ 
W. B. SCOTT 
There remains one family of mammals with which it is necessary 
to deal and that is the camel tribe. This family has two well-defined 
subdivisions, the camels of the Old World and the llamas, guanacos, 
etc., of South America. For a very long time, the family was entirely 
confined to North America and did not reach its present homes until 
the Pliocene epoch of the Tertiary period. ‘The skeleton of a Patago- 
nian guanaco may be taken as the starting point of our inquiry. In 
this animal] the third incisor and the canine are retained in the upper 
jaw, all the incisors and the canine in the lower. The anterior two 
grinding teeth have been lost and the others are moderately high- 
crowned. The skull is broad and capacious behind, narrow and 
tapering in front. The neck is long and its vertebrae very curiously 
modified. The limbs are long and slender and have undergone nearly 
the same modifications as in the horses; the ulna is greatly reduced, 
interrupted in the middle and its separated portions are fused with the 
radius. In the hind leg the shaft of the fibula has been completely 
1From W. B. Scott, The Theory of Evolution (copyright 1917). Used by 
special permission of the publishers, The Macmillan Company. 
