436 ON THE METHOD OF PALEONTOLOGY 



were in such proportion to one another and to the jaw first discovered, 

 as to accord perfectly with his already ascertained laws of correlation 

 of form in the Deer species, could the validity of his restoration be 

 questioned, because he knew nothing about the purposes of all these 

 parts or their physiological correlation ? 



What additional certainty would he gain by now learning that the 

 Deer had once lived — that it was herbivorous — that its teeth and 

 internal organs were all exquisitely adjusted to its mode of life ? He 

 would say, That is all very beautiful, and I am very glad to know it ; 

 but such considerations did not in the least help me to pick out the 

 bones which belonged to the jaw, nor do they add a grain of cer- 

 tainty to that which I already feel as to the justice of my restoration. 

 Indeed, my method tells me a great deal that yours is quite silent 

 about. I knew empirically that the kind of tooth and jaw placed 

 before me was always associated with horns, with slender limbs, and 

 A\'ith cleft hooves ; but I could never have divined these things fi'om 

 knowing that the jaw and tooth were specially adapted to a herbivorous 

 diet. 



Surely all this is so obvious as to need no great amount of demon- 

 stration, and no less clear is its application to the question. What is 

 the method of paleontology ? How is it that we are able to restore 

 an extinct animal from some fragments of its skeleton ? It is by 

 deduction from those empirical laws of morphology which express the 

 invariable coexistences of structures, so far as observation has yet 

 made them known to us, and it is by this method only. When once 

 the general nature of an extinct animal has been ascertained, the 

 laws of physiology may help us to very useful hints and guesses ; but 

 the fundamental step towards the determination of the nature of any 

 unknown fragment, whether recent or fossil, are purely morpho- 

 logical, and, so far as they are concerned, physiology might be 

 non-existent. 



The truth of what has just been asserted must long have been 

 familiar to every thinking botanical palaeontologist ; and I have never 

 met with any indication, either in their works or in conversation, that 

 the botanists imagined they were guided in their determinations of 

 extinct plants by any reference to physiological correlation, or by 

 any other method than deduction from purely empirical morphologi- 

 cal laws. Nor does the palaeontologist, who concerns himself with 

 invertebrate forms, often seek for help from physiology. In fact, the 

 total absence of any acquaintance with physiology which many 

 excellent palaeontologists manifest, is a curious illustration of the 

 justice of my line of argument, as it nowise interferes with the 



