GEOLOGY IN SEE VICE OF MAK— WATT^ 293 



of the Mesozoic period, at the close of a long and most promising 

 chain of evolution, indicates that there Avas some inherent weakness 

 underlying the line of evolution entered upon by them, which pro- 

 ceeded so far and favorably that it was impossible to retrace the 

 path. This may well have been connected with the substance or con- 

 struction of brain and nerve. If so, this side of evolution has to be 

 seriously reckoned with, and it may be that the fundamental weak- 

 ness of physical as opposed to intellectual evolution brought this 

 flourishing and well-developed group to its end. 



It has, of course been suggested by Searles V. Wood, jr.,^ and 

 others that the destruction of Mesozoic life types was brought about 

 by physical changes; but, apart from the fact that the particular 

 changes supposed b}^ the former did not as a matter of fact occur, 

 the entire explanation provides a cause utterly insufiicient in com- 

 parison with the potency of organic struggle against creatures better 

 endowed with warm blood, adequate brain substance, and the ac- 

 tivity and enterprise springing therefrom. 



In spite of the evidence of acceleration as the higher ranks of 

 animals are reached, and in spite of the extraordinary efficiency of 

 the human brain and all the benefits to the organism it brings about, 

 Ave may Avell be appalled by the aeons which have been used up and 

 the millions of varieties which have passed aAvay in the production 

 of this, the most efficient scientific apparatus yet invented or evolved. 



6. But if it has taken long ages to evolve an animal capable of 

 a broader geographical distribution than any other, with a consti- 

 tution capable of withstanding the Avidest ranges of heat and cold, 

 and of peopling the world from its tropical deserts to its polar 

 wastes; and to endoAv him with a brain by A^rtue of which he has 

 made himself master of the earth and all its living inhabitants; it 

 has taken no less time for the evolution of the many factors Avithout 

 which his present success Avould have been impossible. To pick out 

 a single instance, probably fcAv things in the Avhole story of life have 

 been more fruitful in effect than the appearance of the grasses in late 

 P^ocene times, folloAved by their rapid evolution and spread in the 

 Oligocene and under the direction of the critical events of the 

 Miocene period. Starkie Gardner, in an admirable paper, first 

 drew attention to the vital importance to the animal evolution of 

 the AA'orld in general, and to the Avelfare of man in particular, of this 

 t.tep forAvard. It Avas folloAved by great changes in the insect Avorld, 

 by the rapid production of herbiA-orous mammals endoAved Avith 

 speed, great migratory poAvers, special dental and other anatomical 



•Thil. Mag., Vol. XXIII, 1862. 

 76041— 2G 20 



