WESTON, ON THE ACTINOPHRYS SOL. 117 



ing and closure, some half-a-dozen or more of the tentacles, 

 situated on or about it, Avhich have been gradually thrust from 

 their normal position by the act of its protrusion, now rapidly 

 approach each other with a jerk-like motion, caused by the 

 sudden brino-ing: toijether of their bases. 



With one-eighth of an inch objective I have been led to 

 imagine the valve to be formed of a double layer of the external 

 hyaloid inembrane, the edges of which appear lo adhere to 

 each other tenaciously, notwithstanding the growing distension 

 from within, until the force becomes so great that the lips, as 

 they may be called, suddenly separate, apparently to give \ ent 

 to some gaseous product, and at this moment there is, as I have 

 stated, enough seen to induce the belief in the existence of a 

 double lip-like valve, jj^rhaps the organ of respiration. A 

 rough sketch,* PI. IX., fig. 6 c, shows the valve distended. 

 The power employed was two-thirds objective, and No. 2 eye- 

 piece of Smith and Beck. 



The mode of feeding in the Actinophrys Sol has not, I think, 

 been accurately given. That the tentacles possess some other 

 power than that of mere prehension appears to me evident, 

 because nearly every creature of moderate, and sometimes im- 

 moderate size, which strikes against them, is at once, for a time, 

 rendered immovable ; when a Rotifer, in crossing the field 

 with velocity, strikes against an object, the rotatory organ is 

 frequently seen quickly to suspend its operation, the more 

 particularly should its cilia strike the cilia of another ani- 

 malcule ; frequently no notice whatever appears to be taken 

 of the shock, except a sudden change in its course ; not so, 

 however, with the victim to the Actinoj)hrys Sol, on \.\\e instant 

 of contact with whose tentacles it appears paralyzed. 



In some cases the prisoner is held for some seconds on the 

 exact spot where it struck, and then, without any visible means, 

 becomes attracted towards the body of the A. Sol, gliding 

 slowly down the tentacle until it is jammed between its base 

 and a neighbouring one. In another instance (in the same 

 creature) instead of the prisoner being arrested on or near the 

 extremity of the tentacle at which it strikes, it is shot down to 

 the base with extreme rapidity, to occupy the same position 

 as in the former case. In a third it would seem as if the 

 appetite of the Actinophrys were sated, or that the prisoner 

 was not approved of, for after remaining stunned, sometimes 

 for a few seconds, four or five, sometimes much longer, ciliary 

 motion (of a Vorticella, for instance) is feebly commenced in- 

 ternally, not with sufficient energy to produce motion, but, as 



* We are unable to obtain the assistance of an artist here, or the 

 sketches should not have been rough. 



