EVOLUTIONAL GEOLOOY. 291 



d( ) I dwell on these facts ? To depreciate Lvell '. \\\ no moans. No one 

 i.s niore conscious than I of the no1)le service Avhich Lvell rendered 

 to our cause; his reputation is of too roljust a kind to suffer from my 

 unskillful handling-, and the fame of his solid contributions to science 

 will endure long after these controversies are forgotten. The echoes 

 of the combat are already dying away, and uniformitarians, in the 

 sense already defined, are now no more; indeed, were I to attempt to 

 exhibit anj^ distinguished living geologist as a still surviving supporter 

 of the narrow Lyellian creed, he would probably feel, if such a one 

 there be, that I was unfairly singling him out for unmerited obloquy. 



Our science has become evolutional, and in the transformation has 

 grown more comprehensive; her petty parochial days are done, she is 

 drawing her provinces closer around her. and is fusing them together 

 into a united and single commonwealth — the science of the earth. 



Not merely the earth's crust, but the whole of earth-knowledge is 

 the subject of our research. To know ail that can be known about 

 our planet, this, and nothing less than this, is its aim and scope. 

 From the morphological side geology inquires, not only into the 

 existing form and structure of the earth, but also into the series of 

 successive nn^rphological states through which it has passed in a long 

 and changeful development. Our science inquires also into the 

 distribution of the earth in time and space: on the physiological 

 side it studies the movements and activities of our planet; and not 

 content Avith all this it extends its researches into wtiology and en- 

 deavors to arrive at a science of causation. In these pursuits geol- 

 ogy calls all the other sciences to her aid. In our connnonAvealth 

 there are no outlanders; if an eminent physicist enter our territory 

 we do not begin at once to prepare for war, because the very fact 

 of his undertaking a geological inquiry of itself confers upon him 

 all the duties and privileges of citizenship. A physicist studying 

 geology is l)y definition a geologist. Our only regret is, not that 

 physicists occasionally invade our borders, but that they do not visit 

 us oftener and make closer acquaintance with us. 



EARLY HISTORY OF THE EARTH — FIRST CRITICAL I'ERIOD. 



If 1 am bold enough to assert that cosmogony is no longer alien to 

 geology. I may proceed further and. taking advantage of my temerity, 

 pass on to speak of things once not permitted to us. I propose, there- 

 fore, to offer some short account of the early stages in the history of 

 the earth. Into its nebular origin we need not inquire; that is a sub- 

 ject for astronomers. We are content to accept the infant earth from 

 their hands as a molten g-lobe ready made, its birth from a gaseous 

 nebula duly certified. If we ask, as a matter of curiosity, what was 

 the origin of the nebula, I fear even astronomers can not tell us. 



