lO 



ELEMENTS OF MAMMALIAN ANATOMY 



The injecting mass is prepared by thoroughly mixing loo c.c. 

 of water, 20 c.c. of glycerin, 20 c.c. of concentrated formalin, 

 and 85 gm. of common laundry starch. One-half should be 

 colored yellow by adding powdered chrome yellow and the 

 other colored blue by dissolving in it a gram 

 or two of soluble Berlin blue. These liquid 

 masses, after being passed through a fine 

 wire strainer or a coarse piece of cheese-cloth 

 stretched across a funnel, may be preserved 

 for any length of time in covered jars. 



The animal may be anesthetized by plac- 

 ing it in a tight box and administering il- 

 luminating gas, ether or chloroform. If 

 only the arteries are to be infected, the cat 

 may remain in the box until dead; but if 

 the veins are also to be injected, it is pref- 

 erable to use illuminating gas for the 

 anesthetic and then remove the animal to 

 the tray as soon as it is unconscious, and 

 reflect a portion of skin, exposing the ex- 

 ternal jugular veins (Fig. 2). With the 

 curved forceps thrust beneath the vein a 

 cord may be pulled through and tied in a 

 loose knot. One-half inch from the latter 

 a second cord should be tied around the 

 vein loosely. An oblique cut (Fig. 3) with 

 Fig. I.— Injecting the point of the scissors directed caudad is 

 />, Plunger handle; then made in the veins between the cords. 



b, barrel; pi, nozzle; j^g incision should extend about half-way 



c, cannula; r, rubber * 



tube; dt, point of de- through the vcsscl. Absorbing the blood 

 tachment; s, string, ^^j^ absorbent cotton as it runs from the 



vessel will prevent clogging. If too much ether has not 

 been used, the blood will continue running fifteen minutes. 

 When it has nearly ceased flowing the carotid artery must be 

 found by making a slit in the muscle alongside of the trachea 



