48 MR. F. E. BEUUAIUJ ON THK 



§ Histurical Survey. 



There is no doubt that the fullest general account of the 

 intestinal tra,ct of birds written by the older anatomists is that of 

 John Hunter*. He examined and annotated upon more than 

 fifty species not wholly though ma,inly British. His observations 

 are entirely correct, though not always quite full enough. In many 

 cases, however, he has seized the main features of the intestinal 

 coils so accurately and sufficiently that but little in the way of 

 addition is needed. Thus in the Gallinaceous birds he has 

 appreciated the loose ari'angement and absence of fixed loops in 

 the postduodenal section of the small intestine and the attachment 

 of its terminal I'egion to the duodenum. In the Rails he has 

 correctly described the three distinct loops of the jejunal region 

 and the attachment of the fii'st and third of these together. In 

 the Accipitres the short loop just above the cpeca is described in 

 many forms. The peculiaiities of the Parrot intestine are fully 

 described. In short. Hunter accomplished a gi'eat deal. 



Cuvier and Duvernoy t distinguished perfectly correctly, as Dr. 

 Mitchell has pointed out, the three separate regions in the sma,ll 

 intestine of a bird, which I pi-opose to call duodenal, jejunal, 

 and ileic loops, and they also indicated the fact that the middle of 

 the three loops is frequently folded upon itself, contorted into a 

 spiral, or subdivided into several regions. Furtheiiuoi'e. it is 

 iema,i-ked (and I find myself in accord with this opinion) that, 

 '• le canal intestinal des oiseaux est loin de presenter des differences 

 anssi nombreuses, d'une espece, d'un genre ou d'une famille 

 a I'autre, que celui des mammiferes." Thereafter follows a 

 considerable amount of detail concerning these difFei'ent loops 

 in the different groups of birds. For example, the three simple 

 loops of the Passerines are referred to in a good many species and 

 the spiral arrangement of the middle or jejunal loop is described 

 in the Crows. The Picarian birds, Touracou and Cuckoo, are de- 

 scribed in such w^ords as to show tha,t they agree completely with 

 the Passerines. Cuvier did not, however, as Dr. Mitchell has also 

 a,nd quite justly pointed out, delimit the middle region correctly. 

 He describes the limits of the third (and last) region of the small 

 intestine as indicated sometimes on the side of the middle loop by 

 a,n unpaired ctecum (?'. e., Meckel's diverticulum). This is never 

 the case, I believe +. 



In his ' Lectures oil Comparative Anatomy,' Sir Everard Home § 

 has figured the coils of the small intestine in a number of birds— 

 for instance, the Raven, wdiere the spiral of the jejnnum and tlie 

 close association of the ileic and duodenal loops are indicated ; the 



* ' Essays and Observations,' ed. bj^ R. Owen, vol. ii., London, 1861. 



t ' Le9o"ns d'Anatomie comparee de Geor.oes Ctivier,' rec. et publ. par G. L. 

 Duvernoy, t. iv. 2me partie, Paris. 183o, p. 269 et seq. 



X But see for a possible exfei)tion tbc account of the Tinanious below, p. 52. 



§ ' Lectures on Couijiarative Anatomy,' London. 1814, vol. i. p. 402, vol. ii. 

 pis. civ. ~c\-ii. I am indebted to Dr. Mitchell for the exact r.'ferrnce to th's more 

 than once misqnotetl work. 



