50 
THE NAUTILUS. 
and orders likewise. I say “ most ” because some would not inter- 
grade ; for contrary to the old adage, nature does sometimes jump. 
The theory of descent, and the connection of distinct, recent species 
by their extinct ancestors being admitted, we may next inquire what 
convenient artificial limits may be erected to defined the “ species; ” 
for all scientific investigation would be at a stand still if we have no 
names whereby to designate the various organisms about us. Prob¬ 
ably the only definition of any use is that a species is any assem¬ 
blage of similar individuals of presumably common ancestry, which 
cannot be connected by living intermediate specimens with other 
groups of individuals. It is the break in the chain which allows us 
to constitute the species; and whether this break be wide or narrow 
is of little importance so long as no recent organisms intermediate 
in characters are known . 2 However this idea may be worded, there 
is no possible foundation for species on any other basis. Now, many 
species, especially those having a wide range of distribution, show in 
some parts of their range considerable modifications usually correl- 
lated with peculiarities of climate, soil, or other factors known or 
unknown of their environment. These modifications are often 
sufficient for specific separation were it not for the fact that in some 
localities the links connecting the extreme forms occur. We have 
here species in process of making, waiting only for the extinction 
of the intermediate individuals or for the further intensification of 
the differential characters, to become full-fledged specific types. It 
is obvious that science must take cognizance of these incipient 
species, if it is to be a true record of nature; and for this reason 
“ subspecies ” or “ varieties ” are recognized. Of course they “ run 
into ” each other in some part of their range, otherwise they ivould 
be species. To ignore these varietal forms would be not removing 
obstructions from “ the high-way of the Omnipotent ” as Mr. Weth- 
erby says, but a piece of the most pedantic falsity. The far-reach¬ 
ing importance of these local or geographic “ subspecies ” will be re¬ 
cognized when we understand that in them we have the material of 
future species in the making. We have moved away from the Dar¬ 
winian conception that species have arisen from favorable variations 
of occasional individuals, preserved by the action of natural selec¬ 
tion or “survival of the fittest” ; and now we see much reason to 
believe that the whole mass of individuals over a given area of 
changed or changing conditions, is simultaneously remoulded, not 
2 The question of hybrids need not be considered here for obvious reasons. 
