1862.] FALCONER PLAGIATJLAX. 365 



Notwithstanding the evidence supplied by the brain-case, teeth, and 

 bones of the fore- arm, Cuvier persisted in regarding the animal to 

 be a Rodent, and in the ^Eegne Animal,' of 1829*, he places it 

 between the Squirrels and Marmots. If, with such a fuU measure of 

 evidence before him, the position of Cheiromys in the natural system 

 was so long erroneously contested by Cuvier, how little warranted 

 should we be to pronounce dogmatically upon the food and habits of 

 Flagiaulax from the slender evidence of the lower jaw ! Supposing 

 that Cheiromys were only known to us through its mandible, what 

 would now be its inferred position among the Mammalia? While, 

 therefore, regarding Plagiaulaoc to have been of a phytophagous type 

 in its affinities, we should not be justified in affirming that it may 

 not have been a mixed-feeder ; it may have fed on buds or fruits, 

 like the Phalangers ; or on roots like Hypsiprymnus ; or on a mixed 

 regimen of fruits and insects, like the Aye-Aye. 



But I maintain that every argument which has been adduced by 

 the author of ' Palaeontology ' to prove that Flagiaulax was car- 

 nivorous has been met in the preceding pages. The methods by 

 which the opposite conclusions have been arrived at are as diiferent 

 as the results themselves. Professor Owen, in so far as his. method 

 is disclosed to us, has gone direct from the indications of form to the 

 supposed function ; and he claims for the inferences, that they are 

 physiological deductions. Comparative anatomists will decide how 

 far they are entitled to the name. Mere external form must be 

 handled with caution as an instrument of research ; signal mistakes 

 in Palaeontology have been committed through too confident reliance 

 upon it. On the other hand, the method which I have attempted 

 to pursue was, first to ascertain upon what morphological plan the 

 teeth of Flagiaulax were constructed, and, having determined this, 

 to supply the rest empirically by comparison with known forms, 

 using at the same time rational analysis where it could be applied, 

 e. g. to the condyle. The case is of sufficient interest and importance 

 to test the sufficiency of the respective modes of analysis. 



In the general remarks appended to my former communication, I 

 called attention to the contradictory bearing of the dental system of 

 Flagiaulax upon the assumption that the earliest Mammals had the 

 full complement of teeth. To that fact may now be added the fur- 

 ther evidence of specialization, in the analogy of its mandible with 

 that of the Aye-Aye, one of the most exceptional of Mammals. If 

 we cast a glance over the instructive table given in Lyell's ' Supple- 

 ment' (page 23), and reflect on the interpretation of the hiatus 

 between the Upper Oolitic beds and the ' Sables de Bracheux,' how 

 vast the interval in time by which they are separated, and how 

 modern in comparison the earliest of Tertiary Mammals ! If, on 

 the other hand, Flagiaulax be regarded through the medium of the 

 view advocated with such power by Darwin, through what a number 

 of intermediate forms must not the genus have passed before it at- 

 tained the specialized condition in which the fossils come before us ! 

 What a variety of Mammals may we not hope to disentomb from 

 * Op. fit. p. 195. 



