886 



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 Avioeba, Adinosphmrmm, and other rhizopods have drawn in 



B 

 Fig. 178. — Amaha. A, Normal ; B, after tetauic 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 obsei'ved. The pseudopodia are then 



Pig. 179 — Actinosphterium. A, Undisturbed ; B, at tlie beginning of strong tetanic stimulation ; 

 C, in complete mechanical tetanus. 



incompletely retracted. The phenomena in long, thread-like 

 pseudopodia, such as in Actinosphairium or Orhitolites, are 

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

 the pseudopodia remain smooth and straight, as they were when 



