2S4 THE AMERICAN MONTHLY [Oct., 



In the gathering; rn)iM the I'hipp (."oiisiMvaturv befoiv lucn- 

 tioned, the host of Amoebas there found were associiited with 

 Kuglena. C'oleps, Closterium, Trarlielomonas and several »)ther 

 genera of Infusoria and luioropliytes. One sliile under exami- 

 nation eontained nearly lifty Amoebas and several Stentors. 

 The last. Strntur polymnrphus, while eciualing the Amoeba in size 

 and strength is far more active. When viewing tiie objects on 

 this slide, attention was arrested by the sight of an Am()(l)a 

 partly tnveloping the foot of a Stentor. The attacked animal- 

 cule, though in evident alarm, had not sense enough to loosen 

 it* foot from the glass slide, but tore oft' and left a part behind 

 for the Anurba to make a meal of. So curious a sight natur- 

 ally excited much interest, and led to a search for more inci- 

 dents of the same kind of which quite an unexpected numl)er 

 soon turned up. 



Presently another Stentor appeared in the field having tlie 

 middle jiart of its body enclosed by an Amoeba and rather se- 

 verely pinched at two jioints. With more judgment than the 

 first one, this Stentor, though in a worse plight, drew itself out 

 of the deadly cavity and swam away leaving nothing beliind to 

 .satisfy its hungry captor. This incident is shown in Figure 8. 



The cavity formed to enclose its prey has smooth walls which 

 appear somewhat darker tlian the remaining i)ortions of the 

 Amo'ba's body. So peculiar and characteristic is the appear- 

 ance of this cavity, tiiat one finding it vacant may always be 

 sure some prey has just escaped. When an animalcule is inside 

 and sufficient time allowed, the opposite margins fuse together 

 forming a closed chamber from which there is no escape unless 

 the ca])tive is strong enough to rupture the Amoeba. If left 

 empty, the cavity quickly collapses and disai)pears. 



Further search next brought into view the unexpected spec- 

 tacle of two Amoebas attacking one Stentor. The latter was 

 half enveloj)ed by one Amoeba while its foot was partly seized 

 by the other, but an escape was easily effected without injury. 

 Figure 4 represents this. • 



Ere long a solitary Amceba and Stentor were found engaged 

 in a struggle which continued for some time with varying suc- 

 cess, finally ending in the escape of the latter. At one timetheii 

 Stentor was almost entirely within the cavity, and had time 

 V»een allowed for fusion of the edges, escape would have been 



