THE VISCEHA. 225 



adipose tissue, particularly around the vessels. It consists of four layers, the 

 two internal of which are formed by the saccus epiploicus. Its vessels (from 

 artt. and vv. gastro-epiploica dextra and sinistra) descend between the anterior 

 layers and ascend again between the posterior, anastomosing with those of 

 colon transv. Lymphatic glands on the curvature of the stomach and the 

 colon. Nerves from plex. Solaris, along with the arteries. 



Saccus epipkicus, the omental sac, is formed as the peritonaeum passes 

 through the foram. Winsknvii from right to left, above the lobulus Spigelii [to 

 the transv. fissure of the liver, hence] to the lesser curvature (as posterior 

 layer of small omentum), on the posterior surface of the stomach, downwards 

 behind the anterior layer of the great omentum, becomes reflected [back- 

 wards] upon itself and ascends, before the posterior layer, covering the an- 

 terior surface of the Pancreas, and superior third of Duodenum [in front of 

 the anterior surface of the transv. colon, and forming the ant. layer of trans, 

 mesocolon], and inclining to the right it passes out at the foramen of Win- 

 slow, [after ascending upon the crura of the diaphragm, being reflected upon 

 and covering the lobulus Spigelii, and entering the transverse fissure of the 

 liver]. 



458. 4. The Peritonaeum forming the fourth layer [posterior] 

 of the great omentum was traced to the dorsal wall below the 

 Pancreas. Hence it again passes downwards and forwards, thus 

 forming the two layers of which mesocolon transv. consists, and 

 which lie transversely between jejunum and ileum, liver, sto- 

 mach, and spleen. 



459. 5. Turning back (as inferior [posterior] layer of meso- 

 colon trans.), it passes again downwards before the second and 

 third abdominal vertebrae [and the transverse third of the duo- 

 denum] surrounding the numerous convolutions of the jejunum 

 and ileum, and again turning back to the vertebral column (as it 

 forms the root of the mesenterium), it thence descends to the 

 inferior (pelvic) wall before the rectum, &c. 



Mesenterium. The mesentery consists of two curly-folded laminaB which 

 lie close to one another, pass down, vertically, on the left side of the vertebral 

 column [obliquely from the left side of the body of second lumbar vertebra 

 to the right sacro-iliac synchondrosis], receive between them the branches of 

 art. and ven. mesenterica superior, Chyle vessels and Lymphatic glands (gl. 

 mesaraica), and at the concave surface of the small intestines separate from 

 one another, for the purpose of enclosing these organs. 



To the right, left, and below, we find, besides this large inferior inversion, 

 several smaller, which proceed from the dorsal wall and pass into the parts 

 described. They are the incomplete mesenteries for the colon ascendens and. 

 descendens for the ccecu/m and sigmoid flexure, and for the rectum (mesorectum). 



460. The organs of Respiration, Organa respirationis, 



are the lungs, the thorax, the trachea, the larynx and pharynx, 

 and the nasal cavities. 

 15 



