1 54 



ANATOMY OF THE DOMESTIC FOWL 



is reflected upon the pericardium from the linea alba and the middle 

 line of the sternum, and passes deeply into the interspace of the 

 lobes of the liver. It is attached to these lobes throughout their 

 whole length and connects them below to one side of the gizzard. 

 The lateral and posterior part of the Uver attach to the adjacent air 

 cells, and the whole viscus is thus kept fixed in its position during 

 rapid and violent movements of the bird. 



The remains of the umbiUcal veins are traceable within the dupli- 

 cature of the membranes forming the septum. These remains thus 

 represent the round hgament of mammals. 





TifT»4i'sS*! 







'P~^ 



Pig. 38. — Cellular structure of liT^er, pancreas, and trachea. 



A. Liver. 1, Liver cells. 2, Sinusoid. 4, Nucleus of cells. 



B. Pancreas, i. Island of Langerhans. 2, Alveolar cell.s. 3, Duct. 



C. Trachea, i. Ciliated epithelia. 2, Glands. 3, Hyaline cartilage. 



D. Section of wall of ovum at Fig. S7 letter d. i. Yolk. 2, Granular mem- 

 brane. 3, Theca. 4, Blood-vessel. 



A microscopic study of the Uver of the fowl shows a compact mass 

 of Uver ceUs polyhedral in shape, with large nuclei (Fig. 38, A). 

 The Uver tissue differs from that of mammals in that there is no 

 clearly outlined lobular arrangement; neither is the outUne of the 

 individual ceU so well marked. The parenchymatous portion is 

 made up of columns of liver tissue. These columns anastomose and 

 show narrow channels between. They are best seen in the young 

 chick. 



Function. — One of the functions of the Uver is to secrete bUe. A 

 gall-bladder, which receives part of the bile secreted by the right lobe 

 of the Uver, is located on the posterior face of this lobe. Extending 



