1902.] ADAPTATIONS IN' DIPROTODONT MARSUPIALS. 13 



svibstances (amyltim, fat, proteine), the digestion of which may 

 take place in the small intestine without the help of any caecum 

 and without any specialization of the colon. "Vegetable food may 

 thus, just as well as a carnivorous diet, lead to the loss of the 

 cseciim. He also draws attention to the condition found in 

 the peculiar Phalangerid Tarsipes, in which the ctecum is 

 entirely wanting, and thinks that this depends upon the fact that 

 this animal feeds chiefly on honey. This last statement is of 

 special interest because Tai'sipes belongs to the same family as 

 the animals which are to be considered here ; and it might, with 

 regard to the development of its intestine, be put at one end of 

 the series described below. 



The chief material for this little study was afforded by some 

 specimens of PAa^a?^gre/■ macidatus and Petaurus hreviceps, collected 

 in New Guinea by the late Dr. E. ISTyman ; a specimen of 

 Pseudochirus occicle^italis brought home from Western Australia 

 by the late Captain Forsstrbm ; and a specimen of Trichosurus 

 vulpecula from an unknown locality. In addition to these I have, 

 with the kind permission of my friend Professor T. Tvillberg, had 

 the opportunity of using other available material in the Zoological 

 Museum of the Royal University at Upsala, and I beg to offer 

 him my best thanks for these new proofs of his never-ceasing 

 liberality. 



My first attempt was to try to find out on what kind of diet 

 the above-mentioned animals lived, by carefully examining the 

 contents of the stomach and the intestine. The stomach of the 

 Petaurus contained pieces of the chitinous integument of various 

 insects and larvfe, some whole Podurids, and hair of the animal 

 itself. Among the Podurids my friend E. Wahlgren was able to 

 distinguish specimens of Isotoma palustris and of an Achoriotes. 

 It seems accordingly to be certain that this animal may be termed 

 entomophagous, although pei-haps also berries etc. may enter into 

 its diet. The stomach and the intestine of the Phalanger 

 maculatus were completely filled with fruit-pulp, and there is 

 thus reason to regard this Cuscus as chiefly carpophagous. The 

 stomach in my specimens of Pseudochirus and Trichosurus was 

 empty ; the contents of the intestine and especially the cfecum 

 indicated, however, a vegetable origin. In the ceecum of Tricho- 

 surus comparatively large pieces of the fibrous skeleton of leaves 

 could be found, but the parenchymatous substance was digested 

 or, at any rate, loosened from the " nerves." This agrees well 

 with Lydekker's words — "the highly aromatic leaves of the 

 Peppermint-gum form the favourite food of these animals."^ 

 The csecum of Pseudochirus was filled with a substance in which, 

 under the microscope, various parts of leaves, upper and lower 

 epiderm, bundles of vessels, etc. could be discerned. There was 

 also a good deal of fine sand, which, probably as dust, had once 

 covered the leaves and sprouts on which the Pseiodochirus had 



1 Lydekker : ' A Handbook to the Marsupialia and Monotremata.' London, 1894. 



