118 WESTON, ON THE ACTINOPHRYS SOL. 



if a return to vitality were being effected by struggles ; shortly 

 it is seen to glide ofiF the tentacle (as if this appendage pos- 

 sessed the power both of appropriation and rejection), and 

 frequently, with but little sign of recovered life, it slowly 

 floats out of the field. 



We have now arrived at the point where the intended food 

 is fixed, the next process is as follows : from the margin of the 

 body of the Actinophrys a thin pellucid membrane is pro- 

 jected, up the side of the creature destined for food, which 

 proceeds rapidly, but almost imperceptibly, to surround one 

 side of it ; a similar membrane springs sometimes also from 

 the Actinoplirys, but more frequently from the tentacle on its 

 other side ; these amalgamate on the outer surface of the 

 prisoner, which is thus enclosed in a sac, composed of 

 what I take to be the extended outer vesicle of the Acti- 

 noplirys. This vesicle gradually contracts, or rather seems 

 to return by elasticity to its original position, and the food 

 thus becomes pressed within the body, there to become 

 digested. 



Often before the engulphing was complete, I have seen the 

 return of ciliary movement in the victim, which, when large, 

 exhibits powerful efforts to free itself. This ciliary movement 

 continues long after its total immersion in the body of its 

 devourer, and ultimately ceases as its substance seems to be 

 dissolved. 



In no one instance have I ever seen that crossing of the 

 tentacles described by KoUiker, as one of the means of pre- 

 venting an escape, but, as I before said, I may have been 

 watching a different species. In many instances I have seen 

 half-a-dozen or more prisoners attracted to the tentacles of an 

 individual, each gradually absorbed, and although thus busily 

 occupied, no cessation of the action of the valve takes place. 

 The Actinophrys itself appears as if possessed of the most 

 complete stability ; nothing seems to move it, a free Vorti- 

 cella, almost as large as itself, or a Rotifer of equal dimen- 

 sions, dashes against it, producing scarcely a sign of motion, 

 although the force of the concussion would lead one to expect 

 the little creature would be forcibly driven from its position. 

 Does this stability arise from its spherical figure, and the hold 

 thus given to it by the numerous tentacles arising from its 

 entire periphery ? 



Fig. 6 a of the sketch is intended to show a Chcetonotus 

 larus, engulphed ; h, h, b, three Rotifers fixed between the ten- 

 tacles ; c, the valve. Power used, 2-3rds objective, No. 2 

 eye-piece. 



Fig. 7 a represents a large Vorticclla, seized and surrounded 



