12 DR. E. LONNBERG ON DIGESTIVE [Jan. 14, 



Von Ihering. — " Parastacus." Congrfes International de Zoologie 



a Moscou, Aug. 1892 (dated Rio Grande del Sol, 1892). 

 Lankester. — " Note on GuUand's memoir, entitled ' Evidence in 



favour of the view that the Coxal Gland of Limidus and of 



other Arachnids is a modified Nephridium.' " Q. J. M. S. 



vol. xxxiv. p. 427 (1893). 

 LoNNBERG. — " Some Biological and Anatomical Facts concerning 



Parastacus." Zool. Anz. vol. xxi. p. 334 (1898). 

 Von Martens. — Sitzungs-Berichte der Gesellschaft naturforsch- 



ender Freunde zu Berlin, 1870. 

 St. George. — "Ueber eine Zwitterbildung beim Flusskrebs." 



Arch. f. mikr. Anat, vol. xxxix. p. 504 (1892). 



2. On some remarkable Digestive Adaptations in Diprotodont 

 Marsupials. By Dr. Einar Lonnberg, C.M.Z.S. 



[Received November 18, 1901.] 

 (Text-figures 4-6.) 



"While dissecting for other purposes some Phalangerids, my 

 attention was attracted by the great difierence in the develop- 

 ment of the intestine in the different species. As some of the 

 observations made at the time are of a certain interest, the 

 following account of the comparison of the conditions found in 

 the different animals may perhaps be acceptable. 



Before I proceed to report upon my own investigations, some 

 preliminary remarks may be made concerning the views of 

 other authors in similar cases. 



The coi'respondence between an animal's diet and the develop- 

 ment of the different parts of its intestine is a well-known fact ; 

 but, on the other hand, the reason why this must be so has been 

 comparatively little discussed. EUenberger, for instance, has 

 stated that the great development of the caecum in the Horse 

 stands in connection with its diet, which chiefly consists of matter 

 rich in cellulose. The food passes in this animal rather rapidly 

 through the stomach and the small intestine, but is then retained 

 in the c?ecum, where, to a great extent, digestion and absorption 

 take place. In his papers on Rodents, especially in his great 

 work ' Ueber das System der Nagetiere,' Tullberg has expressed 

 the opinion that digestion and absorption of cellulose talve place 

 in the caecum and the colon. He says also that the digestion 

 of this kind of food is not only dependent on the length and width 

 of these intestinal tracts, but also on the slowness with which the 

 food passes through these parts of the intestine. There are in fact 

 to be found many structural adaptations for the purpose of 

 retaining the food or retarding its passage. The same author 

 also discusses the reason why some animals among the Rodents, 

 viz. the Myoxids, have lost their caecum. He believes that such 

 a reduction is the result of a diet chiefly consisting of such 



