THE WAY OF THE WILD 73 
Some utterly useless species are well protected. The miser- 
able little grass, Danthonia spicata, that grows freely over New 
England hills is thickly studded at the base of the stem with 
short but sharp hairy spines that cattle avoid. The nettle is 
covered with fine needlelike hairs which on contact discharge 
minute bits of acid capable of giving a burning sensation to 
people and thin-skinned offenders, but useless with most wild 
animals. The thistle, however, has a weapon worth while. 
Speaking generally, weapons of offense or defense, especially 
the former, are good things to have, and when present are gen- 
erally made the most of; but when absent another way is sought, 
and if one good enough is found, the species can be successfully 
preserved without weapons, as is the case with the antelope and 
deer, which are the gentlest of animals. 
It is notable, however, that the character or part on which 
the species depends most for its existence is most highly de- 
veloped, even though in other respects the animal or plant may 
be very defective. This, of course, is due to the fact that the 
effects of natural selection have been long felt in that particular . 
part, while others have been neglected and left undeveloped. In 
this connection compare the remarkably efficient trunk of the 
elephant with his exceedingly awkward feet, which belong not 
to this but to prehistoric times, and have remained practically 
undeveloped and unchanged since the earliest ages. 
Space could be filled indefinitely with this vast and most in- 
teresting phase of the subject. The important point is, however, 
to note the fact that while weapons are convenient they are not 
indispensable, and that some species that have the least use for 
them have some of the best ones, —bees, for example, —though 
whether in remote times they may have been more useful we 
can hardly say with confidence, because sometimes a sudden 
change in the surroundings renders useless a part that before 
was next to indispensable. Fig. 10 represents a tropical butter- 
fly that spends much of its time on stakes and stubs where it is 
practically indistinguishable from the lichens, especially as it has 
