164 



THE ART OF MAKING MICROSCOPE SLIDES 



Method 



Fig. 87. Injecting a rat through the carotid artery. 



rial, such as milk or a suspension of India 

 ink, is injected into the blood stream, and 

 the natural i)iimi)ing action of the heart is 

 utiUzed to carrj- it to the finest capillaries. 

 The second method is to force the injec- 

 tion medium into the blood vessels of a 

 dead animal in such a manner that it dis- 

 places the fluid already there. One method 



of auto-injection is described in consider- 

 al)lc detail in one of the examples which 

 terminate this chapter. 



Forcing an injection material into the 

 blood vessel of a dead animal is by no 

 means as easy as it sounds. In the first 

 place one has to secure some hollow tube 

 which may be inserted into the blood 



