ON THE METHOD OF TAL^ONTOLOGV 443 



at the end of the argument about the Ungulata, forming not a 

 separate question or opposite case, but part of the same. 



But here as elsewhere, Dr. Falconer seems to forget the important 

 distinction between a question of detail and one of principle. If 

 physiological arguments are good at all in the way Cuvier put them, 

 they must be universal in their application, in which case any ex- 

 ception is fatal ; on the other hand, if the}' be of limited application, 

 before we can apply them in paljeontology, we must first have 

 ascertained to what group the subject of our studies belongs b\' 

 other means, and these can only be the application, of .morphological 

 laws. . _ ■ 



I -trust I have now brought forward- sufficient evidence to justify 

 my accusation of misrepresentation and: misconception . on .Dr. 

 Falconer's part, and I would most willingly leave the subject, were 

 it not necessary in defence of myself and others to advert to one or 

 two other points in Dr. Falconer's attack. In two of these, accuracy 

 as to matters of fact is involved. The first relates to the Stonesfield 

 Mammal, a title which has been applied as much to the Phascolo- 

 therium as to the Amphitherium. Dr. Falconer asserts, that I have 

 been unhappy in my citation of this case, because the Amphitherium 

 is an Insectivore, and because the Phascolotherium has fewer teeth 

 than the Amphitherium. Candour might have led Dr. Falconer to 

 quote a little more of Prof Owen's opinion as to the latter animal 

 than he does.'^ If he had combined careful thought with candour, he 

 would have perceived that inasmuch as the Phascolotherium possesses 

 forty-eight teeth (four more than the typical number in Mammals), 

 and has the strongly inflexed angular process, it precisely fulfils the 

 conditions of my argument. In point of fact, however, the number of 

 teeth is an irrelevant consideration. The other question of fact 

 relates to the structure of the Sloth's tooth ; when Cuvier speaks of 

 the alternation of substance in the teeth of an Ungulate animal, 

 he obviously refers to that peculiar alternation of vertical plates 

 of enamel, dentine and cement, which the teeth of the typical 

 Ungulates present. A difference of structure in layers parallel to the 

 crown of the tooth, is of course possessed by every Carnivore, and it 

 is this kind of arrangement which the Sloth also presents. I venture 

 to think, therefore, that this objection to my argument is like most of 

 Dr. Falconer's, and to use his own words, " more specious than valid." 



1 See British Fossil Mammals, pp. 55 and 56. Professor Owen especially warns us 

 against concluding " too absolutely " that the Amphitherium." may not have combined the 

 more essential points of the Marsupial organization " with the slighter inflection of the angle 

 of the jaw. 



