xxu INTEODUCTION 



near the tip, so that it may be firmly secured in the vessel by 

 a ligature. The largest cannula that will enter the vessel 

 should be used. 



2. A glass syringe, capable of holding about an ounce of 

 fluid. A larger syringe is liable to get blocked up. 



3. Several pieces of strong india-rubber tubing, about an 

 inch long, to connect the nozzle of the syringe with the 

 cannula, both of which they must fit rather tightly. 



4. Two or three glass plugs to fit the india-rubber tubing. 



5. A dish of water or salt-solution, in which all the eannulse 

 and india-rubber connections are laid, to displace the air from 

 them. 



6. Fine plaster of Paris. 



7. A mortar and pestle. 



8. Colouring matter, such as carmine previously rubbed 

 up with water : it must be well shaken before use. 



9. A piece of muslin to strain the injection through. It 

 must be well wetted before use. 



10. A jar into which to strain the injection. 



11. A jar containing about half a pint of saltrsolution (-75 

 per cent.), at a temperature of 100° F. 



12. Dissecting-board, pins, scalpels, scissors, two pairs of 

 forceps, seeker, thin string or thread, and two or three pairs 

 of 'bull-dogs.' These last are very short spring-forceps, the 

 spring being so arranged as to close the forceps. They are 

 convenient to stop the escape of blood or injection from any 

 vessel that may have been cut. 



The injection should be performed close to a large sink, 

 over which is a water-tap with a foot or two of wide india- 

 rubber tubing attached. 



When everything is ready, kill the animal, and as soon as 

 it is dead, lay it open, cutting as few blood-vessels as possible. 

 Expose the root of the aorta or other vessel from which it is 

 intended to inject the animal ; choose a cannula of the right 

 size : fit it with an india-rubber connection ; fill it with salt- 

 solution, and stop the end of the connection with a glass plug. 

 Pass a ligature round the vessel : make a longitudinal slit in 

 the vessel ; insert the cannula ; tighten the ligature upon it. 



