28 DR. J. MURIE AND MR. A. D. BARTLETT [Jan. 9, 



5. On the Movement of the Symphysis of the LoAver Jaw in 

 the Kangaroos. By James Murte, Prosector to the 

 Society, and A. D. Bartlett, Superintendent of the So- 

 ciety's Gardens. 



A short time ago, a lady, a frequent visitor at the Gardens, on 

 conversing with the keeper of the Kangaroos, asked him if he was 

 aware of the manner in which these animals used the teeth of the 

 lower jaws to snip their food as a person would do in snipping grass 

 with a pair of scissors. She mentioned that she had resided many 

 years in Australia, and seemed quite positive as to the truth of the 

 fact that Kangaroos used their lower incisors in the manner already 

 spoken of. The keeper, interested in what had been told him, called 

 the attention of Mr. Bartlett to it. 



Mr. Bartlett immediately examined the teeth and jaws of several 

 skulls of Kangaroos in his possession, and, satisfied of the probable 

 truth of the remark, took the first opportunity of observing the same 

 in the living animals in the Society's Collection. 



Since then we have corroborated and added to these observations 

 together. The following were the different species of the living 

 animals examined for this purpose, — viz. the Red Kangaroo (Macro- 

 pus rufus), the Black-faced Kangaroo (M. melanops), the Great Kan- 

 garoo (M. giganteus), the Yellow-footed Rock Kangaroo (Petrugale 

 xanthopus), Bennett's Wallaby (Halmaturus bennettii), and the 

 Derbian Wallaby (H. derbianus). 



In these several species we noticed the following movements : — 

 As the animal opened its mouth and seized the grass offered it, there 

 was a slight though distinct separation of the lower incisors, differing 

 in each individual according to its size, — in the large Kangaroo almost 

 as much as a quarter of an inch. 



The small mouthful of grass being seized, the green blades were 

 cropped or nipped off, a portion being evidently cut through by the 

 anterior free sharp edge of the two lower incisors as they pressed 

 against the opposing concavity of the palate and the cutting-edge 

 of the upper and anterior incisors ; while another portion of the 

 food passed between the two lower incisors, and seemed also to be 

 snipped through either by the closure or approach of the trenchant 

 internal lateral edges of these, or it might be by the jerking move- 

 ment of the head, which caused the morsel to be half torn and half 

 cut through by these incisors. At other times, when the grass was 

 in small loose bundles of a few of the stronger fibres with their roots 

 attached, instead of chewing the latter, the animal rather rejected 

 them ; but in order to do so grasped the roots or dry portion of the 

 stem, which it wished to disengage, with its fore paws, using the claws 

 in the manner a human being would the fingers and hands to clutch 

 and drag an object. While doing this, what stalks were between 

 the lower incisors were severed by their internal acute borders. 

 After the grass had thus been cut through, it was passed between 



