Marsh. 1 89 



systems, we find that the " age of fishes " has passed, and 

 instead, there are remains of gigantic crawling and winged 

 reptiles ; creatures, of which we can form no conception 

 from the study of the reptiles of to-day, were then abun- 

 dant, and this period has been called the " age of reptiles." 

 Ages again pass ; vast changes of temperature and climate 

 occur ; the large reptiles become extinct ; the Tertiary rocks 

 appear, and the " age of Mammals " (of which man is one) 

 is reached, although a few remains of mammals are found 

 in the Secondary rocks. The abundance of fossils of Mam- 

 malia in the Tertiary strata, furnish us with a great deal of 

 material for study, and we find traces of a progressive 

 development from extinct forms to those which now exist on 

 the earth. Many of the animals whose remains are dis- 

 covered, have long since become extinct; but man, who may 

 have had a hand in their extinction, as he certainly has in 

 that of many in recent times, has certainly lived side by 

 side with some of them, and by means of his peculiar ability 

 to adapt himself to his environment, as well as by his skill 

 in overcoming his enemies, has been enabled, in spite of 

 his comparatively weak physical development, to survive 

 them in that struggle for existence which is going on be- 

 tween the stronger and the weaker of Nature's children. 



The remains found in the earth show that, whilst under- 

 going development in the direction of becoming more civi- 

 lized, man passed through four distinct stages. These are 

 known as the Palceolithic or Old Stone Age, the Neolithic or 

 New Stone Age, the Bronze Age and the Iron Age. During 

 the first two of these periods, the use of metals appears to 

 have been unknown, the weapons used by man having been 

 made principally of flint, bone or wood. The weapons are 



