FORM OF THE CONTINENTS— WATTS 203 



times. By the Oligocene they had made good their hold, peculiari- 

 ties in their growth and structure enabling them to compete with 

 the other vegetation that then existed; and gradually they spread 

 over huge areas of the earth's surface, formerly occupied by marsh, 

 scrub, and forest. They have, as Ruskin says, "a very little strength 

 . . . and a few delicate long lines meeting at a point . . . made, as 

 it seems, only to be trodden on today, and tomorrow to be cast into 

 the oven"; but, through their easy growth, their disregard of tram- 

 pling and grazing, and by reason of the nourishment concentrated 

 in their seeds, they provided an ideal and plentiful source of food. 

 On their establishment we find that groups of animals, which had 

 previously browsed on shrubs and trees, adopted them, with conse- 

 quent alterations and adaptations in their teeth and other bodily 

 structures. To follow their food from overgrazed or sun-scorched 

 regions they required to be able to migrate easily and quickly, and 

 it was essential for them to discard sedentary defense and to flee 

 from threatened danger. Such defense as was possible with heels, 

 teeth, or horns, they retained; but the dominant modifications in 

 their organization were in the direction of speed as their most vital 

 need. 



Side by side with this development, and in answer to increasing 

 numbers, came bigger, stronger, and speedier carnivores, to feed on 

 prey now so much more abundant, but more difficult to catch. The 

 answer of the grass-feeders, with their specialized hoofs, teeth, 

 and bones, better suited to flight than fight, was to seek safety in 

 numbers, and thus develop the herd instinct, with its necessity for 

 leadership and discipline ; but this, in turn, provoked a like rejoinder 

 from some types of their enemies. 



When it is remembered how much of the meat and drink and life 

 of mankind is bound up with the grasses, including wheat, maize, 

 millet, and other grains, sugarcane, rice, and bamboo, we must 

 realize how close is his link with the development just outlined. 

 Practically his whole food supply is provided by them, either directly 

 by the agriculturist who grows little else but grasses, or indirectly 

 by the herdsman whose domestic animals are fed chiefly on the same 

 food. Nor must we forget that almost every one of our domesticated 

 animals has been derived from the gregarious types just mentioned, 

 which have accepted the leadership of man in place of that of their 

 own species. 



It is perhaps not too much to say that the magnificent outburst of 

 energy put out by the earth in the erection of the Alps, Andes, and 

 Himalayas in Tertiary times was trivial in its influence for man's 

 advent and his successful occupation of the earth in comparison with 

 the gentle but insidious growth of "mere unconquerable grass" and 



