186 



DE. P. CHALMERS MITCHELL ON THE 



SPHENISCIFORMES. 



I have already described and figured the intestinal tract of Eudyptes (26.^%. 6). I 

 now am able to add descriptions of the condition in Spheniscus demersus (fig. 7) and 

 Aptenodytes Pennanti (fig. 8). In all three the intestine is extremely long and of 



Fig. 6. 



Intestinal Tract of Tachyba^ttes jtuviatilis. Lettering as before. 



slender calibre with firm walls; in the figures the actual length is somewhat under- 

 estimated, so that the " correction " for piscivorous diet has been made partially. The 

 three portions of the tract are well marked and are each drained by a characteristic 

 factor of the portal vein. The duodenum is extremely long ; it is thrown into a 

 complicated set of minor loops resembling the condition in the fish-eating Eagles, in 

 Eudyptes and Spheniscus ; in Aptenodytes it forms a loosely rolled spiral, a mode of 

 packing increased length that is not at all uncommon among birds and that must 

 be regarded as a multiradial apocentricity. Meckel's tract in all three is moderately 

 specialized ; Meckel's diverticulum lies nearly at the middle of its course, but there is a 

 strong tendency for the numerous minor loops to be extended in length or expanded 



