228 THE DESCENT OF MAN. Part I.. 
species ” might here be used with much propriety. But 
from long habit the term “ race ” will perhaps always 
be employed. The choice of terms is only so far im- 
portant as it is highly desirable to use, as far as that 
may be possible, the same terms for the same degrees of 
difference. Unfortunately this is rarely possible ; for 
within the same family the larger genera generally 
include closely-allied forms, which can be distinguished 
only with much difficulty, whilst the smaller genera 
include forms that are perfectly distinct ; yet all must 
equally be ranked as species. So again the species 
within the same large genus by no means resemble 
each other to the same degree : on the contrary, in 
most cases some of them can be arranged in little groups 
round other species, like satellites round planets . 19 
The question whether mankind consists of one or 
several species has of late years been much agitated by 
anthropologists, who are divided into two schools of 
monogenists and polygenists. Those who do not admit 
the principle of evolution, must look at species either 
as separate creations or as in some manner distinct 
entities ; and they must decide what forms to rank as 
species by the analogy of other organic beings which 
are commonly thus received. But it is a hopeless en- 
deavour to decide this point on sound grounds, until 
some definition of the term “ species ” is generally ac- 
cepted ; and the definition must not include an element 
which cannot possibly be ascertained, such as an act of 
creation. We might as well attempt without any defi- 
nition to decide whether a certain number of houses 
should be called a village, or town, or city. We have a 
practical illustration of the difficulty in the never- 
19 ‘ Origin of Species/ 5tli edit. p. 68. 
