ADDRESS: Ixvii 
bones by numerals, which, when adopted, may take the place of names ; for 
then all propositions respecting the centrum of the occipital vertebra might 
be predicated of ‘1’ as intelligibly as of ‘ basioccipital.’ The name appears 
to be now generally accepted, and why not the symbol? The symbols of 
the teeth are as definite as those of the bones; and, in the absence of single 
names, more useful, since they render unnecessary the repetition of the com- 
pound definitions ; they harmonize conflicting synonyins, serve as a universal 
language, and express the writer’s meaning in the fewest and clearest terms. 
_ The entomologist has realized the advantage of signs, such as 6, ?, &c. for 
male, female, neuter, and the like; and the time is come when the anatomist 
may avail himself of this powerful instrament of thought, instruction, and 
discovery, from which the chemist, the astronomer, and tle mathematician 
have obtained such important results. 
To William Sharp Macleay, author of the ‘ Hore Entomologice,’ belongs 
the merit of first clearly defining and exemplifying, in regard to the similarities 
observable between different animals, the distinction between those that in- 
dicate ‘affinity’ and those that indicate ‘analogy’ or representation. This 
distinction has been well illustrated by Vigors in the class of Birds, and has 
been ably discussed by Swainson in reference to other classes of animals. 
‘ Affinity,’ as first defined by Macleay in contradistinction from ‘ analogy,’ 
signifies the relationship which one animal bears to another in its struc- 
ture, and is the closer as the similarity of structure is greater. Swainson 
illustrates this idea by comparing a goatsucker with a swallow and witha 
bat: with the one its relation is iné¢mate, with the other remote: the goat- 
sucker has affinity with the swallow, analogy to the bat. 
But the idea of the foregoing intimate relation of entire animals, called 
‘affinity,’ is different from the idea of the answerable relation of parts of 
animals called ‘ homology.’ Animals, however intimately ‘aftined,’ are never 
the same in the sense in which homologous parts are so esteemed: they 
could never be called by the same name, in the way or sense in which a bone, 
for example, of the fore-limb, is called ‘ humerus’ in the goatsucker, swallow, 
and bat. 
There is, indeed, a sameness in the idea of ‘analogy,’ as applied by the 
Zoologist to animals, and by the Anatomist to their parts. The goatsucker is 
related by analogy toa bat, because, as Mr. Swainson remarks, “ it flies at the 
same hour of the day, and feeds in the same manner; ” and the membranous 
wing of the bat isanalogousto the membranous parachute of the dragon, because 
it serves to sustain the body in the air. That is to say, ‘ function ’—a similar 
relationship to a tertium quid—in the above instance air,—is the groundwork 
for predicating analogies in regard to parts as well as wholes; more espe- 
cially when, as in the case of the wings of the dragon and bat, they are not 
homologous parts. 
The study of homologous parts in a single system of organs—the bones 
—has mainly led to the recognition of the plan or archetype of the highest 
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