416 THE HAND AS AN UNRULY MEMBER. 
existed in past ages, this constituting the science of Palæ- 
ontology. 4. Then comes Physiological Anatomy, which 
treats of organs in reference to their functions; and, 
lastly, there is what is called Homology, in which parts 
and organs are considered, not according to their size, 
or shape, or the specific functions which they perform, 
since these vary greatly in different species, but accord- 
ing to their essential structure and their connections with 
other parts; these last are called morphological charac- 
_ ters, and they alone are sufficiently constant to serve as 
the basis of zodlogical classification. This branch of 
anatomy is generally followed with a view of determining 
and comparing corresponding or homologous organs in 
different animals, but the same methods may be employed 
in another way, which has been in existence for hardly a 
century, and for which no name has yet been fully ac- 
cepted ; it consists in the determination and comparison of 
corresponding parts in different regions of the same indi- 
vidual. 
To illustrate the distinction between these two kinds of 
Homology, by reference to familiar objects, the former 
would compare the foremast of one ship with that of an 
other, and note their difference in the size and proportion 
of the various pieces; while the latter would compare the 
foremast with the mainmast of the same ship, pointing 
out their resemblance, and the differences in the length 
of the various pieces. 
It is to this latter kind of anatomy that I propose 
to call attention, and have chosen for a subject an orga? 
which, though small, is most comprehensive, gathering 
within its grasp far more than can be illustrated in this 
short article, —the Hand. 
It is a time-honored theme, and he stands in great dan- 
