THE ANIMAL ORGANS. 39 



throat until it enters the stomach ; its connection below with the duodenum 

 should then be followed. The white glandular organ called the pancreas, or 

 sweetbread, may next be traced, attached to the bent part of the duodenum, 

 and reaching across to the left ; and lastly the dark purplish organ called the 

 milt or spleen will be found attached to the left side of the stomach itself. The 

 gullet being now tied below the diaphragm, all these parts should be removed ; 

 when the two kidneys, more rounded than in man, with the supra-renal bodies 

 surmounting them, their ducts or ureters leading from them, and the great 

 bloodvessels in the middle line, viz., the abdominal aorta and the inferior vena 

 cava, will come into view. The knotted cords of the sympathetic nerve will also 

 be seen. 



In the thorax, the two lateral compartments formed by the right and left 

 smooth-surfaced pleurce will be immediately observed, each containing its own 

 lung, which light pinkish-white spongy organs will be found to have shrunk a 

 little so as no longer to fill their respective pleural sacs ; at the back part of 

 each lung its attached portion or root will be discovered, upon which the pleura 

 passes to cover the lung itself. By pulling on the roots of the lungs, their con- 

 nection with the windpipe is easily proved, as that part is seen to move ac- 

 cordingly. Air should also be blown down through a glass tube into the 

 windpipe, by which means the lungs will be instantly inflated. Between the 

 two lungs and partly overlapped by them, is the pericardium, the bag or sac 

 in which the heart is contained : this must be opened, to show the heart in its 

 natural position, having its free point or apex turned towards the ribs, and its 

 broad attached base directed towards the back. The pericardium may now 

 be snipped away from the diaphragm, and also from the great bloodvessels, 

 which are seen springing from the base of the heart, and passing upwards to 

 the neck, and sideways to the roots of the lungs. The great bloodvessels at 

 the root of the neck, branching some to the head, and others to the upper 

 limbs, may next be divided, together with the windpipe, and then all these 

 parts, with the heart and lungs, may be stripped off downwards : on being 

 laid upon a board and examined from behind, the course of the trachea or 

 windpipe and its two branches or bronchi, as they go to the lungs, may be dis- 

 tinctly traced. There remain in the thorax itself, the thoracic portions of the 

 aorta and the gullet, the course of which last, from the neck down through the 

 diaphragm, may be again demonstrated by aid of a quill. The diaphragm 

 itself may now also be studied. It is useless to search for the thoracic duct, 

 which, however, lies behind the gullet, upon the vertebral column. With 

 care, the knotted cords of the sympathetic nerves may be found, one at each side 

 of the spine. 



The upper remaining portion of the windpipe may next be traced up to the 

 cartilaginous box, called the larynx, and the gullet up to the pharynx. At 

 the side of the face and neck, just between the lower jaw and the ear, will be 

 found the principal salivary gland, called the parotid gland ; another, the sub- 

 maxillary, lies below the jaw in the neck. The lower jawbone may now be 

 split or cut through in the middle line, and its right half detached from the 

 parts beneath and taken away at the joint near the ear : this opens one side 

 of the mouth, and pharynx ; and the opening thus made should be extended 

 down the gullet. The tongue with the sublingual glands being drawn aside, 

 the slit-like aperture, called the glottis, which leads into the larynx and so into 

 the windpipe, is seen ; and also a small valve, called the epiglottis, which falls 

 back from the root of the tongue over this opening. A quill passed backwards 

 through each nostril will show the communication of the nasal cavities with 

 the upper part of the pharynx. The ear should be removed as close as possi- 

 ble to the head, to show the passage leading into the temporal bone, which 

 contains the internal chambers of the ear. The eyelids may be divided at their 

 outer corner and reflected back, to show the position of the eyeball, with its 

 muscles and stalk-like nerve, lodged in the eyesocket or orbit. 



The cranium should now be opened by a transverse saw-cut, made carefully 

 through the bone only, above the orbits, met by two others running back to 

 the occipital foramen. The top of the skull thus separated is to be raised up 

 in front by a blunt chisel, and pulled off forcibly backwards. The dura mater 

 thus exposed is, with its smooth arachnoid lining, to be cut along the same 



