INJECTION WITH CORROSIVE SUBLIMATE. 



17 



Injection of a frog" with corrosive sublimate and preparation 

 of its tissues for microscopical examination. A frog, killed with ether, is 

 laid on its back on a frog plate in a zinc tray. Divide the skin in 

 the middle line from the centre of the 

 abdomen to within half an inch of 

 the mouth, raise the skin and note 

 where there are large cutaneous vessels, 

 make two transverse cuts so that the 

 skin can be turned back freely, arid 

 open the body cavity near the middle 

 line, avoiding the central vein in cutting 

 through the muscles of the abdomen. 

 Next raise the sternum by its cartilage 

 with forceps, free it and divide the ribs 

 on each side, and turn it upwards, thus 

 gaining free access to the heart. Open 

 the pericardium, hold the heart so as 

 to put the aortse on the stretch, and with 

 fine forceps pass a thread under each 

 near its origin, scraping through the 

 confining connective tissue to do so. 

 Form a loop on each thread ready for 

 tightening. Next raise the heart, snip 

 into the sinus with scissors, cut off the 

 apex of the ventricle, and let all the 

 blood escape. Wash away blood from 

 the body cavity with normal saline. 

 Tie the right aorta, and into the left 

 introduce a fine glass cannula through 

 the opening in the ventricle. The 



FIG. 5. Simple class appliance for fixing animal tissues by injection. 



1 The same principles will apply for injecting any small mammal, i.e., mouse, rat, 

 small kitten or rabbit, or a separate organ. 



