xi THEORY OF DESCENT 139 



The question is, indeed, so far-reaching, so all -pervading, 

 that it meets us everywhere in the study of every group of 

 animal or vegetable life, and in almost every aspect in which 

 the study can be carried out. 



It bears largely upon, and is greatly illustrated by, de- 

 scriptive zoology or botany. It adds vastly to the interest 

 of the pursuit of anatomy, by calling out the meaning of 

 rudimentary structures and so-called typical resemblances ; it 

 elucidates obscure questions relating to the habits and instincts 

 of animals ; it brings into prominence the signification of 

 various facts of geographical distribution, and the life it throws 

 into the study of palaeontology is too obvious to need remark. 



Evidences bearing upon, either for or against, the theory 

 of evolution or descent can be collected from all these sources. 

 I need only refer to Mr. Darwin's works, which must be 

 familiar to you all, in illustration of the great variety and 

 number of the branches of science which can be brought to 

 throw light upon it. Indeed, in a subject like this, where 

 direct observation can count for little, in consequence of the 

 extreme shortness of the observing time of any individual 

 compared with the enormous period required for the assumed 

 changes, it is only by the accumulation of a vast number of 

 facts from various sources, and observing the direction in 

 which they all point, that anything like proof can be obtained. 



Leaving aside, for the present occasion, all other sources 

 of evidence in favour of either of these views, I propose this 

 evening to enter only upon one which is in some respects, as 

 all must admit, the most important, as it comes nearer than 

 any other to show what actually has been the history of our 

 existing species in times past ; for as the most natural and 

 conclusive way of ascertaining the method by which a nation 

 has arrived at its present condition of society, customs, laws, 

 etc., would certainly be to examine into the preserved records 

 of its past history, so it must be with the present condition of 

 animal and vegetable life. 



We all know that such records have been preserved, that 

 the solid rocks beneath our feet in many places teem with the 

 actual remains of creatures which lived and died thousands or 

 millions of years ago. 



