Jan., 1892. 
DRAGONS OF THE PRIME. 
7 
is composed of a single bone, the upper end of which works 
directly on the lower end of the tibio-tarsus. In the Dinosaurs, 
however, the third section of the limb, which obviously 
corresponds to the third section of the bird’s limb, is made up 
not of one, but of three separate bones , while between them and 
the second section of the limb are two rows of small bones which 
apparently are not present at all in the bird. 
(4).—In each animal there are four toes, three larger, and 
one smaller; each animal, too, walks on the toes, and not on 
the soles of the feet. 
If, now, we compare the Dinosaur limb with that of a 
crocodile, we shall find that really they are very similar. 
The difference between them lies in the position of the bones 
which form the sole of the foot. In the crocodile these are 
four in number and lie flat on the ground ; in the Dinosaur 
they are raised from the ground and are three only. 
The Dinosaur’s limb, then, seems to resemble the typical 
reptilian limb more than the bird’s; it resembles the bird’s 
limb in being divided into four parts, and in beiug digitigrade; 
it differs from the bird in the fact that there are three bones 
in the third part instead of one ; and that two rows of small 
bones lie between the second and third parts, which are not 
present in the bird. The Dinosaur limb, in fact, differs from 
the bird’s in just those points in which it resembles the 
typical reptilian limb. 
If, now, we compare the structure of the limb in an 
embryo bird (Fig. 6, A.) while it is still inside the egg with that 
of a Dinosaur (Fig. 6, B.), we find a very close resemblance 
between the two. For instance, in the chick, we find that 
the whole limb is divided into four main parts as in the adult, 
but the fibula instead of being shorter than the tibia is just 
as long, as is the case in the Dinosaur. 
Then, again, the third section of the limb is made up not 
of a single bone, as in the adult, but of several separate bones, 
as in the Dinosaur. The resemblance to the limb of the 
latter is completed by the presence between the second and 
third parts of the limb of two rows of bones. (Fig. 6, T lt T a .) 
In these bird-like Dinosaurs, then, the hind limbs have 
quite the structure of the embryo bird; hence, we can say 
either that the Dinosaur has the limb of an embryo bird, or 
the embryo birdhas the limb of the adult and specialisedreptile. 
The apparent great difference between the structure of 
the limb in the embryo and that in the adult bird is due to 
the coalescence of various parts; thus the four separate 
meta-tarsals of the third part of the limb (Fig. 6, A M.) join 
together to form a single bone (Fig. 6 B Tm.), and also at 
