"PLIMMER'S BODIES" 181 



of lymphocytes. In the first instance a dilute extract 

 was made in citrate solution, kept at 60 C. for twenty- 

 four hours, and then filtered. Some fresh blood was 

 mixed in a capillary tube with an equal volume of the 

 filtrate and incubated at 37 C. for three hours. A drop 

 of the mixture was then examined on the stained jelly 

 which excites amoeboid movement in leucocytes (kinetic 

 jelly). It was at once seen that the coefficient of 

 diffusion of the leucocytes and lymphocytes had fallen 

 remarkably a greater fall than had ever been seen 

 except that produced by morphine. The nuclei actually 

 stained on this jelly in about fifteen minutes; and this 

 jelly will never stain the nuclei of normal leucocytes 

 for they burst before that happens. It was also noticed, 

 however, that the cells contained oval vesicles within 

 their cytoplasm which closely resembled "Plimmer's 

 bodies." After a while these bodies became identical 

 with diffusion- vacuoles of large size, and when they 

 burst some of them resembled archoplasm. It may 

 be noted that other authors have suggested that 

 "Plimmer's bodies" and archoplasm are identical. We 

 think that these vesicles induced in leucocytes by the 

 extract are diffusion-vacuoles due to the lowered 

 coefficient of diffusion. 



The next series of experiments was made to observe 

 the effects of this extract of haemal gland on leuco- 

 cytes when the cells are spread on jelly which contains 

 the extract. The jelly-films also contained the correct 

 amount of Unna's stain to stain the granules of the 

 cells, so that, if the extract had any action on the 

 individual cells under these conditions, they would be 



