GENERAL PHYSIOLOGY 



teeth, or to fasten them upon a thin glass slide upon one limb of 

 a tuning fork of the proper pitch and draw a violin bow across the 

 other limb. Observation immediately after the experiment shows 

 that Amoeba, Actinosphcerium, and other rhizopods have drawn in 



A B 



FIG. 178. Amoeba. A, Normal ; B, after tetanic stimulation upon a tuning fork. 



their pseudopodia completely and are in the stage of complete 

 contraction, i.e., more or less completely spherical (Fig. 178). If 

 the experiment be interrupted after a brief period of shaking, 

 according to the time of the interruption the various stages in the 

 formation of tetanus can be observed. The pseudopodia are then 



FIG. 179 Actinosphcerium. A, Undisturbed ; B, at the beginning of strong tetanic stimulation ; 

 C, in complete mechanical tetanus. 



incompletely retracted. The phenomena in long, thread-like 

 pseudopodia, such as in Actinosphcerium or Orbitolites, are 

 characteristic (Figs. 179 and 180). With very slight shaking 

 the pseudopodia remain smooth and straight, as they were when 



