OF THE PROTOZOA. ACTINOPHRYINA. 249 



bending, expansion, and fission of the tentacles. I could not, however, 

 retain this opinion: an extension of a mucons substance, apparently the 

 parench}Tna, really takes place from the side of the Act'mo]phrys ; and this is 

 afterwards drawn in with the prey. This expansion sometimes takes place 

 very slowly ; a thick, regularly lobed mass is seen to embrace the object ; 

 and I have once observed this extension Avithout the presence of any prey. 

 I can only compare this process with what takes place in Amoeba ^ Dr. 

 Strethill AYright (in lit.) expresses the same fact in a condensed form, 

 thus : — " In Actinophrys the tentacles bring the food to the sui-face of the 

 ectosarc, which closes over it and cames it to the endosarc." Mr. Weston's 

 observations tend to a similar interpretation of the mode of introduction of 

 food. " From the margin of the body of the Actinophrys,^^ says this gentle- 

 man, " a thin pellucid membrane is projected up the side of the creatui'e 

 destined for food (XXIII. 24-32), which proceeds rapidly, but almost 

 imperceptibly, to siuTound one side of it ; a similar membrane sj)rings 

 sometimes also from the Actinojplirys, 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 Actinopjhrys. This vesicle gradually contracts, or, rather, 

 seems to retiu-n by elasticity to its original position ; and the food thus be- 

 comes pressed within the body, there to become digested." The conclusion 

 to be drawn is, that, after the act of prehension by the tentacles is complete, 

 the retraction of those processes is succeeded by the protrusion of a sort of 

 variable i^rocess, similar to those of Amoeba in character, and also in its mode 

 of enveloping and engulfing the morsel. 



After its admission into the soft substance of the interior, the nutrient 

 matter undergoes a process of digestion, by which, if soft, it suffers complete 

 dissolution and absorption ; but if it contain insoluble matter, this remains 

 behind, after the disappearance of the rest, as a residue to be sooner or later 

 cast out through an apertiu-e temporarily formed at the point of the surface 

 it comes into contact with, and of which aE. trace is lost so soon as the act of 

 extrusion is accomphshed. The molecular and granular matters derived fi^om 

 food coUect especially in the central or nuclear portion of the body, the depth 

 of coloiu', opacity, and strength of which are directly proportionate to the 

 supply of food. The particle of food (the animalcule or other substance), 

 when in the interior, is surrounded by or suspended in a drop of fluid, or, in 

 Dujardin's phi^aseology, occupies a vacuole. This fluid is either di-awn in 

 by the act of inglutition, or is a secretion pom-ed out around the food for the 

 pm-pose of digestion. Claparede takes the latter view, and states that the fluid 

 always exhibits the same pale-reddish colour as the contents of the contractile 

 vesicle, and indicates different refractive powers from those of water. This 

 observation accords with one made by Sclmeider, of the digestive vacuoles of 

 Amoeba. 



The process of digestion is slow. Claparede observed the changes of a 

 Chlamydomonas, and states that three hours scarcely sufficed for its conver- 

 sion into an unrecognizable gelatinous mass. KoUiker represents the time to 

 vaiy from two to six hom^s ; but this must differ jDerpetuaUy according to the 

 nature of the food, the \itality of the animal, &c. '' The number, as well as the 

 size," writes Kolliker, " of the morsels taken at one time by the Actinojyhrys 

 is very various. Yeiy frequently there may be 2, 4, or 6 at the same time, 

 frequently also more than 10 or 12. Ehrenberg counted as many as 16 

 stomachs, i. e. in other words, so many separate morsels. He also noticed the 

 ingestion of indigo, which could not have gained admission in any other way 

 than that by which the Infusoria and other ahmcnts enter. The largest morsels 



