42 LECTURES 



be considered worthy of dispute. To me, the most re- 

 markable part of the whole question is that so many fair 

 and candid men, using such a variety of physical data, 

 should, in reality, arrive at such a comparatively uni- 

 form result after all. 



Yet 30,000,000 of years "gives us no adequate con- 

 ception of the time involved in the geological history of 

 the earth. For rocks disintegrated into soils and de- 

 posited as sediments are again reconsolidated into rocks, 

 lifted into land-surfaces to be again disintegrated into 

 soils, transported and deposited as sediments. And thus 

 the same materials have been worked over and over 

 again, perhaps many times. Thus the history of the 

 earth, recorded in stratified rocks, stretches out in ap- 

 parently endless vista. And still beyond this, beyond the 

 recorded history, is the infinite unknown abyss of the un- 

 recorded. The domain of geology is nothing less than (to 

 us) inconceivable or infinite time." (Le Conte.) 



With the brief sketch I have given of the distribution 

 of existing animals, and the still briefer account of the 

 divisions of geologic history and the enormous lapses of 

 time that measure those immense ages, we may now pro- 

 ceed to show that it is through the science of palaeon- 

 tology that biology is linked to the very important science 

 of geology. 



Broadly speaking, palaeontology treats of the fossil re- 

 mains of animals and plants as they occur in the earth's 

 crust. It takes into consideration their structure, their 

 taxonomy, their affinities both with extinct types and 

 forms yet existing. Moreover palaeontology is the hand- 

 maiden of geology, inasmuch as it is through its aid, or 

 the employment of the life-system, we are enabled to de- 

 termine and limit the several eras, ages, periods, etc., in 

 geology. In this sense it acts as a check upon the alter- 

 native method of establishing the divisions in geology, of 

 which we speak, or of the employment of the rock-system 

 to which reference has already been made. 



As I have said in a previous lecture one of the great 

 departments of palaeontology is palaaobotany, the science 

 that deals with the fossil florae of the world; and in an- 

 other, though less strict sense, the science of archaeology 

 in reality falls within the domain of palaeontology, as in 

 the main it treats of the works of extinct races of men. 

 My reasons have already been advanced for including 

 palaeontology, palaeobotany. and archaeology, all within the 

 limits of the science of biology where in reality they each 

 and all belong. 



