DISEASES OF THE DIGESTIVE ORGANS. 49 



Plate III. — Instruments used in treating diseases of digestive organs — Contd. 

 drawn, and the temperature read as in any ordinary thermometer. The 

 clinical thermometer is made selt'-rt'gistering ; that is, the mercury in 

 the stem remains at the height to which it was I'orced by the lieat of 

 the body until it is shal^en back into tlie b\dl) liy talking hold of the 

 upper portion of tlie instrument and giving it a sliort, shaip swing. 

 The normal temperature of cattle varies from 100° to 10:!° F. In 

 young animals it is somewhat higher than in old. The thermometer 

 is a very useful instrument and frequently is the means by which 

 disease is detected before the appearance of any external sign. 



Fig. 2. Simple probang, used to dislodge foreign liodies, lilce apples, i iota- 

 toes, eggs. etc.. which have become fastened or stuek in the esophagus 

 or gullet. 



Fig. 3. Grasping or forceps probang. This instrument, also intended to 

 remove obstructinns from the gullet, has a spring forceps at one end in 

 the place of the cup-like arrangement at the end of the simple probang. 

 The forceps are closed while the probang is being intmduced ; their 

 blades are regulated by a screw in the handle of the instrument. This 

 probang is used to grasp and withdraw an article which may have 

 lodged in the .gxiUet and can not lie forced into the stomach by use of 

 the simple probang. 



Fig. 4. Woeden gag, used when the probang is to be passed. The gag is a 

 piece of weed which fits in the animal's mouth; a cord jiasses over the 

 head to hold it in place. The central opening in the wood is intended 

 for the passage of the probang. 



Pig.s. 5a and -"id. Trocar and cannula ; on shows the trocar covered by the 

 cannula ; 5h, the cannula from which the trocar has been withdrawn. 

 This instrument is used when the rumen or first stomach becemes 

 distend(>d with gas. The trocar covei-ed by the canrmla is forced into 

 the rumen, the trocar witlidrawn, and the cannula allowed to remain 

 until the gas has escaped. 



Fig. 6. Section at right angles through the abdominal wall, showing a 

 hernia or rupture. (Taken from D'Arborval. Dictionnaire de JlJdecine, 

 de Chirurgie de Hygiene) : a a. The abdominal muscles cut across; r, 

 opening in the abdominal wall permitting the intestines i I to pa.ss 

 through and outward between the abdominal wall and the skin; p p, 

 peritoneum, or membrane lining the abdominal cavity, carried through 

 the opening o by the loop of intestine and forming the sac S, the outer 

 walls of which are marked b f b. 

 Plate IV. INIicroscopic anatomy of the liver. The liver is composed of innu- 

 merable small lobules, from ■^\ to i\f inch in diameter. The lobules 

 are held together by a small amount of fibrous tissue, in which the 

 bile ducts and larger blood vessels are lodged. 



Fig. 1 illustrates the structure of a lobule; r r, interlobular veins or the 

 veins between the loliules. These are branches of the portal vein, 

 which carries blood from the stomach and intestines to the liver; c c, 

 capillaries, or very fine bloo<l vessels, extending as a very fine network 

 between the gro\u« of liver C(>lls from the interlobular vein to tbe 

 center of the lobule and emptying there into th(^ intralobular vein to 

 the center of the lobule; r c, intralobular v(-in, oi- the vein within the 

 lobule. Tins vessel passes out of the lobule and there becomes the 

 sul^lobular vein; v s. .sublobular vein. This joins other sinnlar veins 

 and heliis to form the hepatic vein, through which the blood leaves 



33071°— 16 i 



