162 The Evolution of Arms and Arvfior. 



foe, the activity of limb that could fly to it, from it and 

 around it, the shrewdness of mind that could observe its 

 habits and select the best points for its attack, and the in- 

 stinct of co-operation that could join forces in coping with 

 it, differing only in their fineness from the sharpness of 

 the tooth and the strength of the claw. And thus were 

 introduced the two great principles that Nature has used 

 in all her arming, and that have played and are still play- 

 ing a most tremendous part in her economy, their dis- 

 tinction being not exactlj'" that of defensive and offensive 

 weapons, for both, when need required, could be used de- 

 fensively, but that the one had its chief value in its own 

 outside strength, while the other depended for its efficacy 

 on qualities connected with its possessor's inside develop- 

 ment. 



Equipped from her arsenal with the varied arms and 

 armor which embodied, some of them one of these principles 

 almost exclusively, and some a mingling of the two, Nature 

 sent forth her myriad creatures into their great life-battle, 

 world-wide in its field, where the issue has been not only 

 which of themselves, but which of their weapons and of 

 the principles on which their weapons were made, would 

 prove the fittest, and best help their users to survive. Dur- 

 ing the long geologic ages they were all, and especially 

 the outward kinds, enormously developed both in size and 

 strength, and their underlying philosophy was tested in the 

 severest way by contests alike with each other and with 

 the world's equally ferocious natural elements. The Ortho- 

 ceras, a huge cephaloid mollusk of the lower Silurian 

 rocks, had a thick, hard, cylindrical covering, twelve to 

 eighteen feet long and at its base a foot in diameter. The 

 Dinichthys, a Devonian ganoid fish some thirty feet long, 

 was protected about its head with a suit of massive articu- 

 lated armor that a cannon-ball could hardly have crushed. 

 Among the famoiis reptiles of the Jurassic and Cretaceous 

 ages, the Icthyosaur, Megalosaur, Mosasaur, Iguanodon 

 and others, some were fifty, sixty, and a hundred feet 

 long, plated over Avith thick scales for defense, and armed 

 for attack with claws hooked back like sickles, with long 

 projecting tusks that shut down by each other like clasped 

 fingers, and with sharp, glistening sabre-like teeth, some- 

 times four rows of them, and two hundred in number, 

 indeed " monstrous and prodigious things worse than fables 



