THE WAY OF THE WILD 73 



Some utterly useless species are well protected. The miser- 

 able little grass, Danthofiia spicata, that grows freely over New 

 ' .ngland hills is thickly studded at the base of the stem with 

 lort but sharp hair)' spines that cattle avoid. The nettle is 

 •vered 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 

 rhe former, are good things to have, and when present are gen- 

 Lilly 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 

 i 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 



