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Show 12 DR. E. LONNBERG ON DIGESTIVE [Jan. 14, YON IHERING.-" Parastacus." Congres International de Zoologie k Moscou, Aug. 1892 (dated Rio Grande del Sol, 1892). _ LANKESTER.-" Note on Gulland's memoir, entitled ' Evidence in favour of the view that the Coxal Gland of Limulus and ol other Arachnids is a modified Nephridium.'' Q- J- M-. ©. vol. xxxiv. p. 427 (1893). LONNBERG.-" Some Biological and Anatomical Facts concerning Parastacus." Zool. Anz. vol. xxi. p. 334 (1898). Y O N 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. E I N A R L O N N B E R G , 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 difference in the development 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 m y own investigations, some preliminary remarks may be made concerning the views of other authors in similar cases. The correspondence between an animal's diet and the development 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. Ellenberger, 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 caecum, 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 take 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. H e believes that such a reduction is the result of a diet chiefly consisting of such |