AMCEBOID PHENOMENA. 



23 



amoeboid activity, whilst, on the other hand, a slight decrease in its 

 density has the opposite effect j (2) a certain temperature. In warm- 

 blooded animals the phenomena cease below about 10C. When 

 gradually warmed they become more and more active up to a certain 

 point, the maximum being a few degrees above the natural temperature 

 of the blood. Above this point they become spheroidal and at a 



FIG. 20. CHANGES OF FORM OF A WHITE CORPUSCLE OF NEWT'S BLOOD, SKETCHED AT 

 INTERVALS OF A FEW MINUTES, SHOWING THE INCEPTION OF TWO SMALL GRANULES 

 AND THE CHANGES OF POSITION THESE UNDERWENT WITHIN THE CORPUSCLE. 



FIG. 21. THREE AMCEBOID WHITE CORPUSCLES OF THE NEWT, KILLED BY 

 INSTANTANEOUS APPLICATION OF STEAM. 



a, a coarsely granular cell ; b, c, ordinary cells. The nuclei appear multiple, 

 but are seen to be connected by fine filaments of chromoplasm traversing 

 the protoplasm. 



somewhat higher temperature their protoplasm is coagulated and killed. 

 Acids at once kill the corpuscles and stop the movements. Narcotic 

 gases and vapours, such as carbonic acid gas or chloroform vapour, also 

 arrest the movement, but it recommences after a time if their action is 

 discontinued. 



