AMEBOID MOVEMENT 



n 



plasmic tube, in an ameba of several pseudopods, excepting where 

 there is a wide zone of stationary endoplasm between the streams 

 (Figure I, v, w). But in "fountain currents," such as Rhumbler 



Figure I. Illustrating the various directions of endoplasmic streaming 

 in growing and retracting pseudopods. a, two oppositely directed streams 

 in a pseudopod, one directed toward the base and the other toward the 

 tip of the pseudopod, with a neutral zone between, b, two streams flowing 

 toward each other. Cases c to r are self explanatory, s, rotational cur- 

 rents observed occasionally in various species of amebas. t, "fountain 

 currents," sometimes observed in Amoeba blattae, and rarely in other 

 forms, u and v represent cases of streaming which have not been ob- 

 served and which probably do not occur, w,, similar to v, but with a wide 

 neutral zone between the streams, represents an actual observed case. 

 m and r probably occur only very rarely; no such cases have been seen, 

 but there seems to be no reason why they do not sometimes occur. Ex- 

 cepting m, u, r and v, all these figures were drawn from observed cases 

 of streaming. 



('98, p. 190) described and figured for Amoeba blattae Biitschli, 

 and which may readily be observed in most species of amebas if 

 immersed in a solution of gelatin thick enough to keep the amebas 



