1806.] Life Before Fouih. 281 



armor. This new phase of evolution may have proceeded 

 very rapidly, many forms of early life disappearing, while 

 those that quickly became armored survived. 



What was this exigency ? .Protection, apparently, as is above 

 stated. But protection from what? Against what destruc- 

 tive foe did these ancient animals need such strong defence? 

 Which among them was the rapacious creature whose ravages 

 imperilled the existence of all the others? Certainly not the 

 sponge or the coelenterate ; they feed on smaller prey. The 

 mollusk or the echinoderm, in their agile unclad state, may 

 have been actively predatory, but they were among those 

 forced to seek protection. Of the known forms the trilobite 

 seems most likely to have been the aggressive foe in question. 

 It was the largest, the most abundant, and, perhaps, the most 

 active of them all, its size and numbers indicating an abun- 

 dance of easily obtained food, while its great variety of species 

 points to the existence of varied conditions of food or methods 

 in food getting. 



To all appearances the trilobite was then the lord of life, the 

 Napoleon of that early empire. Awkward and clumsy as such 

 a creature would appear now, it was then superior in size, 

 strength, and probable agility to all other known animals, 

 while its numbers and variety indicate that it was widely dis- 

 tributed and exposed to all the varying conditions of existence 

 at that time. What a hurrying and scurrying there must have 

 been among those small soft creatures to escape this terrible 

 enemy, from whose assaults nothing seems to have availed them 

 but an indurated external covering, too hard for its soft jaws 

 to master. As the prey became protected in this manner the 

 destroyer probably improved in strength of jaw, and there may 

 have been a successively more complete growth of protective 

 devices in the prey and of powers of mastication in the foe. 

 And thus arose the conditions which first made fossilization 

 possible, in the development of a series of armor-clad creatures 

 which were really late comers upon the stage of life, remote as 

 they seem when measured by our standard of time. 



But the story is only half told. The trilobite, as it is known to 

 us, is under armor also. Not only is it clothed in a dermal 

 20 



