118 DIFFUSION- VACUOLES 



cells; because these diffusion- vacuoles will appear only 

 in living cytoplasm. 



Moreover, vacuoles will never appear in normal 

 blood-platelets they are never seen in fresh blood- 

 films. It is necessary to keep the blood in an equal 

 volume of citrated solution of morphia (a 1-per-cent 

 solution of morphine hydrochloride in citrate solution) 

 for four hours at 37 C. A drop of the mixture is then 

 examined on a film of jelly in the usual w r ay, and the 

 film of jelly should have the correct index of diffusion, 

 and be kept at the right temperature and time for 

 the coefficient of diffusion of leucocytes, i.e. 12. The 

 diffusion-vacuoles will then appear in all the blood- 

 platelets. This experiment is a very easy one, and 

 certain in its results. 



The action of the morphia is the same on the 

 blood-platelets as it is on leucocytes and lympho- 

 cytes. It lowers the coefficient of diffusion to a 

 marked degree, and it appears to do this by causing 

 gradual death. Morphia, in the 1-per-cent solution, 

 is a slow poison for leucocytes, for it will kill most 

 of them at 37 C. in about six hours. After incuba- 

 tion for four hours, however, when the cells are placed 

 on the jelly, the cells are still alive, but their coeffi- 

 cient of diffusion is so lowered by the poison that 

 the jelly, instead of merely causing maximum diffusion, 

 now causes diffusion to excess, and the leucocytes 

 and lymphocytes become intensely vacuolated (fig. 

 24). Further, the blood-platelets will now exhibit 

 "red spots." 



In addition to lowering the coefficient of diffusion 



