PHYSIOLOGY 



107 



in rotation as long as the amoeba continues to progress." Thus 

 Amoeba verrucosa may be compared with an elastic sac filled with 

 fluid. Bellinger (1906) studied the movement of Amoeba proteus, A. 

 verrucosa and Difflugia spiralis. Studying in side view, he found 



Fig. 42. a, diagram showing the movement of Amoeba verrucosa in side 

 view (Jennings) ; b, a marine limax-amoeba in locomotion (Pantin from 

 Reichenow). ac, area of conversion; cet, contracting ectoplasmic tube; fe, 

 fluid ectoplasm; ge, gelated ectoplasm. 



that the amoeba (Fig. 43) extends a pseudopod, ''swings it about, 

 brings it into the line of advance, and attaches it" to the substratum 

 and that there is then a concentration of the substance back of this 

 point and a flow of the substance toward the anterior end. Bellinger 



Fig. 43. Outline sketches of photomicrographs of Amoeba proteus 

 during locomotion, as viewed from side (Bellinger). 



held thus that ''the movements of amoebae are due to the presence 

 of a contractile substance," which was said to be located in the endo- 

 plasm as a coarse reticulum.' 



In the face of advancement of our knowledge on the nature of 

 protoplasm, Rhumbler realized the difficulties of the surface tension 



