164 



ciated teeth, more especially those defined by Cuvier as the fittest to yield the required 

 information. 



§ 15. Work of Molars in JTerbivora. — Vegetable substances need for their assimilation 

 not only dividing but crushing and reduction to pulp by commingling of salivary secre- 

 tions during the grinding process. Hence large salivary glands are associated with 

 numerous broad-crowned grinders. Palaeontology is not left in so helpless a condition as 

 it is made to appear in the following passage: — "There is no reason to suppose that the 

 large trenchant premolars [of Thylacoleo'] were not as well adapted for chopping up 

 succulent roots and vegetables as for 'dividing the nutritive fibres' of animal prey"*. 

 But my task has been to show, not only for what they were adapted, but what they did 

 " chop up." " It may have been," proceeds the writer, " some kind of root or bulb ; it 

 may have been fruit"*. And so it may, according to the conditions of life and organiza- 

 tion imagined by Professor Flower, but not according to those of the Creation open to 

 our observations and comparisons. No known herbivorous Mammal is limited to teeth 

 for slicing or "chopping up" vegetable food. 



There is no difference, indeed, between X. and XII. on the main question at issue 

 between them and me ; but they are at variance between themselves on one point. 

 Dr. Falconer was unable to resist the proofs of carnivority from the demonstrated molar 

 dentition of Thylacoleo ; but, having committed himself to a different interpretation 

 of the like dentition in Plagiaulax, he defended his position with an ingenuity worthy 

 of a better cause, and which excited in the author of XII. and others the sentiments 

 expressed by the epithets " masterly," " amply demonstrated," &c. 



Professor Flower, however, with the unmistakable evidences of essential conformity 

 between the dentition of Plagiaulax and Thylacoleo, consistently applied himself to show 

 that Thylacoleo was as good an herbivore as Plagiaulax. He says, "Dr. Falconer, in 

 his anxiety to show that Plagiaulax could not have been carnivorous, has endeavoured 

 to separate it as much as possible from Thylacoleo, laying great emphasis on all the 

 points of divergence that could be found between them. He was evidently under the 

 impression that the latter had been proved to be a carnivorous Marsupial, without 

 staying to inquire into the arguments on which the assumption rested"f . 



Family relations of Thylacoleo and Plagiaulax in the Marsupial Order. — Of the 

 existing groups of pouched Herbivora Professor Flower, in his paper on the Affi- 

 nities of the extinct Australian Marsupial, which is "branded with such a direful 

 title as Thylacoleo carnifex"%, inclines to select the Macropodidce as the one to which 

 that Marsupial belonged ; and, therein, more especially the Hypsiprymni or Eat-Kan- 

 garoos, in which he " sees at once in the great cutting premolar a miniature of that of 

 Thylacoleo" 



In a " Postscript " he derives encouragement of his views from " some remarks ' On 

 the Dentition of Thylacoleo camifex, Ow.,' by Mr. Gerard Krefft, the able Curator of 

 the Australian Museum, Sydney, in the Ann. & Mag. Nat. Hist. vol. xviii. ser. 3, p. 148, 

 * XII. p. 318. t lb. p. 308. i lb. p. 314. § lb. p. 310. 



