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 

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

 men's laboratories. 



As to the theory of Pangenesis, Hooker frankly admitted 

 that the hypothetical * gemmules ' invoked as the mechanism 

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

 mechanisms which escape the senses, could serve as an orderly 

 basis for reasoned investigation till a more plausible hypothesis 

 be brought forward. Meantime, whatever the scientific value 

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

 clearest and most systematic resume of the many wonderful 

 phenomena of reproduction and inheritance that has yet 

 appeared.' 



To the critics of Natural Selection, whether on metaphysical 

 or physical grounds, he made firm reply. Those who reject 

 it on metaphysical grounds with customary appeal to the 

 odium iheologicum, are, so far, outside the pale of scientific 

 criticism. 



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 



