1843-44 
HUNTERIAN LECTURES 
215 
another organ in the same body, by considering 
them in relation to the general nature and powers 
of the entire animal, together with its relations to 
other animals, and to the sphere of its existence, 
that we are chiefly enabled to elucidate the uses 
of the several super-additions which are met with 
in following out the series of complexities of a 
single organ. 
‘ But comparative anatomy fulfils only a part 
of its services to physiology if studied exclusively 
in relation to the varieties of a given organ in 
different animals. The combinations of all the 
constituent organs in one animal must likewise 
be studied ; and these combinations, with the 
principles governing them, or the correlations of 
organs, must be traced and compared in all their 
Varieties throughout the animal kingdom. It is 
m this point of view that I now propose to treat 
Upon the leading facts of comparative anatomy, 
to discuss and demonstrate the organs as they 
ure combined in the individual animal, and, com- 
tnencing with the lowest organised species, in 
tvhich the combination is of the simplest kind, to 
trace it to its highest state of complexity and 
perfection through the typical species of the suc- 
cessively ascending primary groups and classes 
uf the animal kingdom. In short, as my pre- 
vious courses of Hunterian Lectures, agreeably 
tvith the arrangement of the Hunterian Collection, 
have treated of comparative anatomy according 
