80 Blood Vessels. 



ARTERIES AND VEINS. 



Take the aorta of the dog or cat and prepare either 

 in chromic acid mixture or spirit mixture (page 11). 

 Make longitudinal and transverse sections, stain some 

 with logwood and double stain others with pier o- car- 

 mine and logwood (page 36). Mount in Canada bal- 

 sam. Also make transverse sections of the whole aorta 

 of rabbit and of smaller arteries and veins of the same 

 and other animals, prepared as above. Stain with 

 logwood and mount in Canada balsam. Examine these 

 carefully to see the different amount of elastic tissue 

 and non-striped muscle in the different arteries. 



Veins are prepared in the same manner as arteries, 

 but as they are so much slighter in structure it is easier 

 to examine them in situ in such sections as tongue, 

 kidney, &c. 



ENDOTHELIUM OF BLOOD VESSELS. 



To examine the endothelium of a blood vessel it 

 should be opened and then placed for two or three 

 minutes in half per cent, solution of nitrate of silver, 

 and exposed to the light in distilled water until it has 

 become a brown colour. Then pin it out on a cork 

 and tear off with the fine pointed forceps thin strips 

 of the intima. Mount these in glycerine. 



To examine the different coats of a blood vessel 

 separately, it must be macerated for a few days in a 

 2 per cent, solution of bichromate of potash, well 

 washed, and strips torn off from the different coats ; 

 these can be then stained and mounted. 



