436 
MOEPHOLOGY. 
Chap. XIII. 
general pattern seems to have been thus to a certain 
extent obscured. 
There is another and equally curious branch of the 
present subject; namely, the comparison not of the same 
part in different members of a class, but of the different 
parts or organs in the same individual. Most physio¬ 
logists believe that the bones of the skull are homo¬ 
logous with—that is correspond in number and in re¬ 
lative connexion with—the elemental parts of a certain 
number of vertebrm. The anterior and posterior limbs 
in each member of the vertebrate and articulate 
classes are plainly homologous. We see the same law in 
comparing the wonderfully complex jaws and legs in 
crustaceans. It is familiar to almost every one, that in a 
flower the relative position of the sepals, petals, stamens, 
and pistils, as well as their intimate structure, are intel¬ 
ligible on the view that they consist of metamorphosed 
leaves, arranged in a spire. In monstrous plants, we 
often get direct evidence of the possibility of one organ 
being transformed into another; and we can actually 
see in embryonic crustaceans and in many other ani¬ 
mals, and in flowers, that organs, which when mature 
become extremely different, are at an early stage of 
growth exactly alike. 
How inexplicable are these facts on the ordinary 
view of creation! Why should the brain be enclosed 
in a box composed of such numerous and such extra¬ 
ordinary shaped pieces of bone ? As Owen has re¬ 
marked, the benefit derived from the yielding of the 
separate pieces in the act of parturition of mammals, will 
by no means explain the same construction in the skulls 
of birds. Why should similar bones have been created 
in the formation of the wing and leg of a bat, used as 
they are for such totally different purposes? Why 
should one crustacean, which has an extremely complex 
