170 STUDY OF NATURAL HISTORY. 
range all animals according to their organisation, 
certainly carries with it an imposing aspect of 
authority, originating not so much in the high re- 
putation of the author as a comparative anatomist, 
but from the supposition conveyed by the title, that 
it is based upon the internal organisation of the 
animal kingdom; and that all the divisions are 
formed with a primary regard to such consider- 
ations. But what is the real fact ? Where one group 
of animals has been dissected, and their internal 
structure explained, there are twenty which are 
defined only from their external appearance ; so that, 
with the exception of occasional notes introduced as 
subordinate characters, we find that by far the 
largest proportion of the details of this system is 
founded alone upon external form; and that these 
external characters are nearly as much insisted upon 
in the Régne Animal as in the Systema Nature. 
Further than this, indeed, the comparison between 
these admirable works cannot be carried, except that 
each commenced a new era in that science which 
they have so signally benefited. 
(113.) To external form, then, we must chiefly 
resort, if we wish to make the productions of nature 
intelligible to the generality of mankind. We have 
seen that, in the case of man, nature has chosen ex- 
ternal peculiarities to mark the distinction of differ- 
ent races; and it is notorious how universally she 
has employed the same means to distinguish those 
millions of individuals who people the earth; so that, 
by innumerable modifications of the same set of 
features, we are able to recognise a countenance 
with which we are familiar in a crowd of others, 
