edo- 



Figure 10. Graph representing the relation of firmness and thickness 

 of the ectoplasm with the number and character of the pseudopods in 

 different species of amebas. a, the average maximum number of pseudo- 

 pods directing locomotion in the different species of amebas. b, the num- 

 ber of transitional pseudopods, c, the number of static pseudopods. d, 

 the estimated degree of firmness and thickness of the ectoplasm of the 

 various species of amebas, grading that of limicola as i and that of verru- 

 cosa as 6. 



be concluded, then, that the number and character of pseudopods 

 depends in large part upon the ectoplasm- forming capacity of the 

 ameba ; and that this property is intimately associated with the 

 degree of fluidity of the whole mass of protoplasm in the ameba. 

 That the number and character of pseudopods formed depends 

 in large part upon the firmness and thickness of the ectoplasm was 

 said advisedly. For observations indicate that there are other 

 factors which influence the character of pseudopods besides those 

 which also control the formation of ectoplasm. These other fac- 

 tors indicate their presence readily in the details of structure of 

 the pseudopods. Thus the number of directive, transitional or 

 static pseudopods may be the same in two particular species, yet 

 in their intimate structure and appearance they are always found 

 to differ. In bigemma, bilzi and radiosa, for example, the number 

 of static pseudopods when formed is about the same in the three 

 species, but the similarity ends there. For these species differ in 

 the frequency with which pseudopods are formed, in their per- 

 sistence when once formed, in the ratio of length to average 

 diameter, in the general shape, in the frequency with which 

 straight pseudopods are formed, in the speed of their formation 



