146 THE EXCITATION OF AMCEBOID MOVEMENTS 



even in the presence of alkali. But in any of these 

 instances the movements are not comparable to the 

 deliberate extrusions caused by atropine, which are very 

 striking in character, and if once seen will always be 

 remembered. 



We can, of course, make kinetic jelly suitable for 

 the temperature of the blood (it is merely necessary 

 to reduce the content of alkali in the jelly by 3 units, 

 because we increase the temperature by 3 units), and 

 still the excitation occurs, although (and this is a 

 remarkable circumstance) the excited movements are 

 not so marked at the temperature of the blood as they are 

 at that of the room. Many persons who have seen the 

 action of kinetic jelly have disparaged it, saying that 

 they have often seen marked amoeboid movements in 

 leucocytes; but when questioned, the fact is always 

 elicited that they have employed the warm stage. It 

 is the deliberate and constant exaggerated movements 

 which invariably occur in all living leucocytes at low 

 temperatures which constitutes the striking effect of 

 atropine sulphate upon them. Let a control experi- 

 ment be made with a jelly which contains no atropine 

 and no stain either if one wishes to and the difference 

 is immediately apparent. Excited by the alkaloid, the 

 cells with their stained granules, extruding their long, 

 snake-like pseudopodia in all directions, as if they were 

 searching for something (which, as far as can be found 

 out, they are not), form a very pretty picture, which, 

 when seen through the microscope, will be a revelation 

 to those who have only worked with films of dead cells. 



Atropine sulphate is not the only substance which 



