84 STUDY OF NATURAL HISTORY. 
in all the branches of zoology; and of introducing 
several intermediate groups between those which 
Linneus termed orders and genera. But all this 
could not be done without a more rigorous in- 
vestigation, into the structure of animals, than was 
formerly required. The study of internal com- 
parative anatomy was therefore called in to aid 
zoological classification ; without which it was found 
impossible to understand aright the true nature of 
many of the molluscous animals of Linnzeus, or of. 
those stupendous remains of extinct animals found 
in a fossil state. Now, had the employment of this 
new science been limited to such and similar cases 
which really required its aid, from the insufficiency 
of external distinctions, all would have been well; 
but the leaders of this school, more especially 
M. Cuvier, delighted with the success that attended 
their first researches, proceeded at once to proclaim 
that internal anatomy was the only sure basis of the 
natural classification; quite forgetting the fact, that 
external structure was just as important for this 
purpose as internal anatomy; and that the one, in 
most cases, is but an index to the other. To bring 
this home to the conviction of every one, and as an 
illustration of our meaning, let us look to a gallina- 
ceous bird—the common fowl. If, by its general 
shape and external organisation, we can judge of its 
habits, its mode of life, the nature of its food, and of 
its powers of locomotion ; and if the knowledge so 
gained, is quite sufficient for every purpose of re- 
cognition and of classification ; where would be the 
necessity of proceeding further? why should these 
definitions be burthened with others, taken from the 

