CHAPTER V 



PSEUDOPODS AND THE NATURE OF THE ECTOPLASM 



In contrast with the ridge-forming amebas stand those with 

 smooth ectoplasm, such as the common dubia, discoidcs, villosa, 

 and the rarer laureata and annulate,, to mention only a few of the 

 larger forms. In addition to these may be mentioned all the 

 pelomyxas and nearly all the smaller amebas. Much the larger 

 number of species of amebas do not form ridges in the ecto- 

 plasm during locomotion. 



Of all the amebas with smooth surfaces, the most favorable for 

 observation as to the formation of ectoplasm, is the giant laureata 

 (Figure 4), though it is unfortunately of infrequent occurrence. 



Figure 4. Amoeba laureata. This ameba is multinucleate, containing a 

 thousand or more nuclei of the shape shown at the right. Ameba 1000 

 microns long in locomotion. Nuclei 10 microns in diameter. 



This species is as often found in clavate form as with pseudo- 

 pods. In cross section it is circular or nearly so. It is often found 

 with zoochlorella growing in it, upon which it seems to depend 

 largely for food, for it seldom has distinctive food masses in it. 



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