286 



THE AMERICAN MONTHLY 



[Oct., 



continued to vibrate. Reviving in a short time, its violent contor- 

 tions partly forced aside the walls of the cavity making an open- 

 ing through which with some difficulty it squeezed out and es- 

 caped. The phases of this contest are shown in Figures 6, 7 

 and 8. 



Not long after, another battle was witnessed in the micros- 

 copic arena wherein the Amoeba triumphed. Here two Amoebas 

 were joined together and so remained while only one of them 

 attacked and captured the prey. Tlie second Amoeba kept ex- 

 tending protrusions towards the prey but did not come close 

 enough. In this instance the posterior extremity of the Sten- 

 tor was bulged out into a round mass which the Amoeba was ac- 



FIG. 6.— TWO AMOCBAS ENCLOSING A STKNTOR WHICH, INSTEAD OF TRYING TO 

 SWIM AWAY, CONTRACTS WITHIN THE CAVITY. 



FIG. 7.— THE SAME STENTOR AS FIGURE 6 COMPLETELY ENCLOSED IN THE CAV- 

 ITY BETWEEN THE TWO AMCEBAS. 



tively striving to enclose. Like another example, the imper- 

 illed animalcule, while making violent contortions, lacked the 

 wit to loosen its foot and flee from the deadly embrace. Instead 

 of this it seemed to choose an evil for a good, for it simply held 

 onto the glass and struggled until it tore off and left behind a 

 large part of itself to gratify the ravenous appetite of its captor. 

 The remaining part sailed away badly mutilated. Figures 9 

 and 10 illustrate this last combat and its result. 



From the foregoing incidents it would seem that Amoeba has 

 a special preference for Stentor as its prey. Other organisms, 

 upon which Amoeba feeds were scarcely touched at the time 

 while contact with a Stentor almost invariably led to an eager 



