EFFECT OF NATURAL SELECTION 87 
responds at the cost of its life. Manifestly this is because of 
unusual conditions, for if there were very many naked lights in 
the world, relatively speaking, these moths would become ex- 
tinct unless there were a sufficient number of individuals with- 
out this fatal instinct to keep the numbers good, in which case 
a new and real fit would be developed. The cause of the 
present misfit is of course due to the fact that the fatal selection 
is too rare to greatly affect the species; that is, the selection is 
not severe upon the species because, relatively speaking, it is 
not frequently exercised. 
The foot of the elephant has been mentioned as a disadvan- 
tage. The immense branching horns of the stag are certainly 
far from being advantageous to him, or even a good fit with 
his brushy environment, with which they frequently become 
entangled, Many a stag has gone down to his death because 
his horns became entangled in the thicket or locked with those 
of an adversary, and many pairs of antlers are found lying be- 
tween two skeletons, mute witnesses of the final death struggle 
in which the cause of the tragedy was the unfortunate horns 
that are commonly supposed to be protective. 
The present point is, that while this is far from a good fit, 
yet the fatal consequences do not follow with sufficient frequency 
to affect the species. But few males are needed to perpetuate 
the species, and the small number that lose their lives by means 
of their unfortunate horns can well be spared, for they will not 
be needed in the propagation of the new generation. As will be 
readily seen, defects in females are much more dangerous to 
species than are defects in males. 
Adaptation not necessarily perfect. The fit between various 
species and their environment, and the adaptation of their parts 
to the surrounding conditions, are not, therefore, necessarily 
perfect. It must be good enough to insure abundance of offspring 
for the next generation, and that is enough. Any race, therefore, 
can endure any handicap up to this point and prosper, and that 
is why natural selection carries improvement up to a certain point 
