38 THE STUDY OF ANIMAL LIFE CHAP. 



the abode of the strong." Even some of the simplest 

 animals have offensive threads, prophetic of the poison- 

 ous lassoes Avith which jellyfish and sea-anemones are 

 equipped. Many worms have strong chitinoid jaws ; 

 many crustaceans have strong forceps ; many insects 

 have stings, not to speak of mouth organs like surgical 

 instruments ; spiders give poisonous bites ; snails have 

 rasping files ; the cuttle-fish have strangling suckers 

 and parrots' beaks. Among backboned animals we re- 

 call the teeth of the shark and the sword of the sword- 

 fish, the venomous fangs of serpents, the jaws of croco- 

 diles, the beaks and talons of birds, the horns and hoofs 

 and canines of mammals. Now we do not say that 

 these and a hundred other weapons were from their 

 first appearance weapons, indeed we know that most of 

 them were not. But they are weapons now, and just 

 as we would conclude that there was considerable struggle 

 in a community where every man bore a revolver, we 

 must draw a similar inference from the offensive equip- 

 ment of animals. It appears to us, however, that the 

 struggle for existence in the strict sense is not illustrated 

 by what is now part of the every-day routine of all 

 the members of a species and is exhibited uniformly by 

 all, but only by individual and experimental " answers 

 back ' to some special pressure of surrounding limita- 

 tions and difficulties. 



As to armoured beasts, we remember that shells of 

 lime or flint occur in many of the simplest animals, that 

 most sponges are so rich in spicules that they are too 

 gritty to be pleasant eating, that corals are polyps 

 within shells of lime, that many worms live in tubes, 

 that the members of the starfish class are in varying 

 degrees lime-clad, that crustaceans and insects are 

 emphatically armoured animals, and that the majority 

 of molluscs live in shells. So among backboned animals, 

 how thoroughly bucklered were the fishes of the Old Red 

 Sandstone against hardly less effective teeth, how securely 

 the sturgeon swims with its coat of bony mail ! Am- 

 phibians arc mostly weaponless and armourless, but 

 reptiles are scaly animals par excellence, and the tortoise, 



