II SKELETONS OF BIRD AND REPTILE 21 
and unsatisfying in, for instance, the isolated fact that 
a certain bone in a certain part of the skull is called 
the Squamosal (SQ, fig. 10). Something is wanted to 
give point and interest to such dry fragments of ana- 
tomical knowledge, some strange variation in the bone 
in question in different classes of animals, or a theory 
as to the origin of the skull, so that the memory may 
not have to deal with what abhors it more than anything 
else—viz., isolated meaningless facts. There is much 
pleasure to be got by putting the wing of a bird and the 
fore leg of a lizard side by side, and observing the 
changes that have made a fuller and more vigorous 
life possible to the bird. The same kind of interest 
may be found in a general comparison of the skulls. 
But since it is difficult for human weakness to main- 
tain this during the slow groping progress through 
the labyrinth of bones, I shall pass over this part 
of the subject without going into any detail. There 
is, however, something of a clue to the labyrinth. 
Géthe discovered one which will lead us some way, 
though not nearly so far as he imagined. The skull, 
according to him, was simply an expanded vertebral 
column, all its chief bones being vertebra, the name 
given to the series of bones which combine to form 
the neck, backbone, and the bony skeleton of the 
tail, all included in the term vertebral column. 
This is one of the great ideas which advance science. 
Even if it had turned out entirely unfounded, still 
something would have been learnt in the process of 
testing it. But this theory has not proved to be with- 
out foundation. There is no doubt that the skull is 
made up partly of vertebra. But, so far, the difficul- 
