METAPHYSICS AND SCIENCE 117 



neglected by some naturalists and discarded by others, which, 

 under his mind and eye, prove to be of first-rate scientific 

 importance. 



One of Darwin's characteristic faculties, as Sir James Paget 

 ut it, was this power of utilising the waste materials of other 

 len's laboratories. 



As to the theory of Pangenesis, Hooker frankly admitted 

 hat the hypothetical ' gemmules ' invoked as the mechanism 

 f inheritance, were ' not proven,' but like other assumed 

 lechanisms which escape the senses, could serve as an orderly 

 ■asis for reasoned investigation till a more plausible hypothesis 

 •e brought forward. Meantime, whatever the scientific value 

 f the ' gemmules,' the statement of the theory was ' the 

 learest and most systematic resume of the many wonderful 

 )henomena of reproduction and inheritance that has yet 

 ppeared.' 



To the critics of Natural Selection, whether on metaphysical 

 >r physical grounds, he made firm reply. Those who reject 

 fc on metaphysical grounds with customary appeal, to the 

 )dium iheologicum, are, so far, outside the pale of scientific 

 •riticism. 



Having myself [he said] been a student of Moral Philo- 

 sophy in a Northern University, I entered on my scientific 

 career full of hopes that Metaphysics would prove a useful 

 mentor, if not a guide in Science. I soon however found 

 that it availed me nothing, and I long ago arrived at the 

 conclusion, so well put by Agassiz, when he says, ' We trust 

 that the time is not distant when it will be universally 

 understood that the battle of the evidences will have to be 

 fought on the field of Physical Science, and not on that of 

 Metaphysical. 



On the score of geology, there were still some, a dwindling 

 minority, who relied for criticism on the assumed perfection 

 of the Geological Eecord. This gave occasion for the well- 

 known tribute to Sir Charles Lyell, who after upholding the 

 fixity of species for forty years, was led by the researches 

 of his old pupil to abandon it in the tenth edition of the 





