450 



PLAGIAULAX. 



I shall adduce a celebrated case to show how little we 

 should be authorized to pronounce with confidence on the 

 nearest affinities of Plagiaulax from the small measure of 

 evidence we now possess. The Aye-Aye (Cheiromys Mada- 

 gascariensis) was discovered by Sonnerat before 1782. The 

 elder Greoffroy and Cuvier placed it among the Rodents. In 

 1816, De Blainville submitted the skull and teeth, together 

 with the bones of the fore-arm, to a rigorous examination, 

 and convincingly pronounced the Aye-Aye to be a Lemurine 

 Quadrumane. Notwithstanding the evidence supplied by the 

 brain-case, teeth, and bones of the fore-arm, Cuvier persisted 

 in regarding the animal as a Rodent, and in the ' Regne 

 Animal,' of 1829, 1 he placed it between the Squirrels and 

 Marmots. If, with such a full 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 Plagiaulax 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 Plagi- 

 aulax 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 ad- 

 duced by the author of ' Palaeontology ' to prove that Pla- 

 giaulax was carnivorous has been met in the preceding pages. 

 The method by which the opposite conclusions have been 

 arrived at are as different as the results themselves. Pro- 

 fessor 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, tbat they are 

 physiological deductions. Comparative anatomists will de- 

 cide how far they are entitled to the name. Mere external 

 form must be handled with caution as an instrument of re- 

 search ; signal mistakes in Palaeontology have been com- 

 mitted 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 



de baguettes.' (Sonnerat, quoted in 

 Puffon, Supplement, torn. vii. p. 268.) 

 The early account of the French tra- 

 veller has been confirmed by the later 

 and excellent observations of Dr. Sand- 

 with, who fed his captive Aye-Aye upon 

 bananas and dates, the latter of which 



it took to with great relish, gnawing 

 the larvae of insects out of the branches 

 of trees, and feeding on them when it 

 had the opportunity. (Sand with. Zoo- 

 logical Proceedings, 1859, p. 113.) 

 1 Op. cit. p. 195. 



