CAECUM OF RABBIT. 27 



and Krause, /. c. p. 163), but in answer, Bernard appealed to the existence firstly of 

 a second duct in the situation above specified, and secondly of certain accessory 

 pancreatic glands either sessile upon or with ducts opening into the bile-duct (see 

 figures, pp. 350-351, Le9ons sur les proprie'te's physiologiques des Liquides de 

 Porganisme, 1857). The second duct, however, of the pancreas in the Rabbit, 

 though such an accessory duct does exist in several Ungulata, several Carnivora, the 

 Elephant, and the Beaver, has been allowed by Bernard himself not to be constantly 

 present (see Comptes Rendus, /. c. p. 390, and Le9ons de Physiologic ExpeYimentale, 

 1856, ii. p. 271, in which last work it is best described as ' petit conduit pancre"atique 

 exceptionnel venant s'ouvrir dans le canal choledoque ') ; and Krause, /. c., suggests 

 that a branch of the arteria gastro-epiploica dextra has been taken in an uninjected 

 preparation for a duct. As regards the smaller accessory pancreatic glandules in 

 connection with the bile-duct, Bonders and Kuhne have remarked that they would 

 be quantitatively inadequate to account for the emulsification of fatty matters which 

 has sometimes been observed to have taken place in the duodenum above the 

 opening of the pancreatic duct. On the whole, however, it seems that though some 

 emulsification is effected independently of the pancreas, the appearances figured by 

 Bernard, Comptes Rendus, /. c., are so constant as to show that the process is very 

 greatly helped by the secretion in question. For good summaries of the whole 

 question, see Kuhne, Lehrbuch der Physiologischen Chemie, 1868, pp. 131-133, 

 and Foster's Text-Book of Physiology, 4th ed. 1883, p. 295 (ed. 3, p. 279). 

 The existence in certain animals of more than a single duct to the pancreas 

 was first pointed out by De Graaf, in his Tractatus Anatomico-medicus de succi 

 pancreatici natura et usu, pp. 16-17, 1671. The duplex and triplex ductus, how- 

 ever, are illustrated by him only by instances from Birds ; amongst Mammals 

 he only records the presence of a second smaller duct as having been occasionally 

 found in Man and the Dog. See also Nuhn, Lehrbuch der Vergleichenden Ana- 

 tomic, pp. 50-51, 1878. 



7. CAECUM AND PARTS OF LARGE AND OF SMALL INTESTINE 

 OF RABBIT (Lepus cuniculus}. 



With Figure 3. 



THE. lymphatic (or lacteal) sinuses x surrounding the Peyerian follicles 

 in the walls of the vermiform appendix, a, in the dilated termination of the 

 small intestine, c, and in a saucer-shaped patch of glands, d, in the large 

 intestine, have been injected with Berlin blue, so as to show the relation of 

 the lacteal vessels to the Peyerian follicles in the walls of the intestine, as 

 also to certain mesenteric glands left in relation with it. The mesentery 

 connecting the caecum and vermiform appendix with the segments of the 

 small and large intestine has been cut through, and the caecum disposed so 



1 The lymphatic and lacteal vessels of many organs may be readily injected by the simple 

 'Einstichsverfahren' of Hyrtl and Teichmann. It is especially easy to obtain successful results in 

 the case of the Peyerian glands of the Rabbit where, as in Bos and Ovis, the base of the follicles is 

 surrounded by lymphatic sinuses, and not as in man and in the Carnivora by a reticulation of 

 lymphatic vessels. 



