ALTMICNTARV TIlACT OF CICIfTAIX RiriDR. Ul 



broad, <ar>d contrnsts vci-y markedly with tlie duodeiinl loop, on 

 account of the small calibre of the intestinal canal in this region ; 

 the duodenum is particularly wide and tapers off gradually 

 towards the jejunum, the greater part of Avhich is also very 

 narrow ; the tube is, in fact, quite as narrow here as is the ileum. 

 The contrast between the duodenum and the comnaencement of 

 the jejunum on the one hand, and the rest of the jejunum and the 

 ileum on the other hand, is remarkably like that seen in the 

 Gallinaceous birds, e. g., Cr«,r (see p. 55). The ileic loop is as long 

 as the duodenal loop or very nearly so. It is connected to it by a 

 ver}- short ileo-duodenal ligament, which leaves almost the whole of 



Text-fisr. 19. 



Intestinal tract of Tnrnix varia. 

 Lettering as before. 



both loops free of each other. The jejunal region is of considerable 

 length, and lies loosely and irregularly folded in the body-cavity for 

 the most part. The commencement of this part of the intestine, 

 however, where it joins the duodenum is not only, as already 

 mentioned, of greater calibre than the rest, but is fixed in a short 

 and wide and therefore not very well-marked loop. The rest of 

 this section of the intestine lies loosely like the Mammalian small 

 intestine or the jejunum in Gallinaceous birds — that is to say, it 

 has no fixed loops, but can be passed in a straight line between 

 the fingers without tearing or distorting the mesentery which 



5* 



