PHYSIOLOGY 



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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. Dellinger 

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



Fig. 44. 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. 



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

 plasm as a coarse reticulum. Wilber (1946) pointed out that Pelo- 

 myxa carolinensis carries on a similar movement at times. 



Fig. 45. Outline sketches of photomicrographs of Amoeba protexis 

 during locomotion, as viewed from side (Dellinger). 



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

 protoplasm, Rhumbler (1910) realized the difficulties of the surface 

 tension theory and later suggested that the conversion of the ecto- 

 plasm to endoplasm and vice versa were the cause of the cytoplasmic 



