1800.] DAWSON — IDEAS OP DERIVATION. 137 



protracted over half a century, or that still future time predicted 

 in Holy Writ when the days of a man shall be as those of a tree. 

 Having worked out these problems, we would be in a position to 

 inquire as to the possible transiti)a of Homo from or towards any 

 other generic form. I would by no means put forward this theory 

 of embryonic development as including the whole law of introduc- 

 tion of species or genera* any more than the others reviewed, but 

 I must say that to my mind it appears to hold forth the most 

 promising line of investigation, with the hope of arriving ultimately 

 at some true expression of the law of creation with reference to 

 organized beings. 



What that law will ultimately prove to be, and to what extent 

 it may include processes of derivation, it is impossible now to say. 

 At present we must recognize in the prevailing theories on the 

 subject merely the natural tendency of the human mind to grasp 

 the whole mass of the unknown under some grand general 

 hypothesis, which, though perhaps little else than a figure of 

 speech, satisfies for the moment. We are dealing with the origin 

 of species precisely as the Alchemists did with Chemistry, and as 

 the Diluvialists and Neptunists did with Geology; but the 

 hypotheses of to-day may be the parents of investigations which 

 will become real science to-morrow. In the meantime it is safe 

 to affirm that whatever amount of truth there may be in the 

 several hypotheses which have engaged our attention, there is a 

 creative force above and beyond them, and to the threshold of 

 which we shall inevitably be brought after all their capabilities 

 have been exhausted by rigid investigation of facts. It is also 

 consolatory to know that species, in so far as the Modern period, 

 or any one past Geological period may be concerned, are so fixed 

 that for all practical purposes they may be regarded as 

 unchanging. They are to us what the planets in their orbits are 

 to the Astronomer, and speculations as to origin of species are 

 merely our nebular hypotheses as to the possible origin of worlds 

 and systems. 



One word in conclusion with reference to our oWn work here 

 as a Society, and as individual collectors of facts. We may not 

 be in a position to take any leading place in the agitation of the 



* It is but fair to say that Mr. Cope himself admits the action of 

 natural selection as one cause of change. 

 Vol. IV. K No. 2. 



