Although like other animals, the Amœba cannot change inorganic into organic matter, as the vegetable Amœba can do, these two Protozoa are similar in one mode of reproduction; for portions of the animal Amœba or even one of the pseudopodia separate from the gelatinous mass, move to a little distance on the surface of the water, and become independent Amœbæ. With a high microscopic power, many bodies besides the digesting vacuoles and pulsating vesicles may be seen imbedded in the sarcode of the Amœba princeps; namely, coloured molecules, granules, fat-globules, and nuclei. All these bodies were seen by Mr. Carter, in certain Amœbina he found at Bombay, together with what he believed to be female reproductive cells, and motile particles similar to spermatozoids, or male fertilizing particles. [Illustration: Fig. 87. Actinophrys sol.—A, ordinary form; B, act of division or conjugation; C, process of feeding; D, discharge of fæcal matter, _a_ and _b_; _o_ _o_, contractile vesicles.] The Actinophrys, a genus of the order Radiolaria, differs from the Amœba princeps in having a definite nearly spherical form with slender root-like filamental pseudopodia radiating from its surface in all directions as from a centre. They taper from the base to the apex, and sometimes end in knobs like a pin’s head, but vary much in length and number, and can be extended and retracted till they are out of sight. They are externally of a firmer substance than the sarcode of the body, which is merely a viscid fluid inclosed in a pellucid film. The Actinophrys sol, which is the type of the genus, is a sphere of from 1/1300 to 1/650 of an inch in diameter, with slender contractile filaments the length of its diameter extending from its surface as rays from the sun. It can draw them in and flatten its body so as to be easily mistaken for an Amœba. This creature, which is common in fresh-water pools where aquatic plants are growing and even in the sea, has little power of moving about like the Amœba; it depends almost entirely on its pseudopodia for food. They have an adhesive property, for when any animalcule or diatom comes in contact with one of them, they adhere to it; the filament then begins to retract, and as it shortens the adjacent filaments apply their points to the captive, enclose it, coalesce round it, the whole is drawn within the surface of the Actinophrys, the captive is imbedded in the sarcode mass, and passes into a vacuole where it is digested, and then the pseudopodia thrust out the undigested matter by a process exactly the reverse of that by which the food was taken in (D fig. 87). The pseudopodia are believed by Professor Rupert Jones to have the power of stunning their prey, for if an animalcule be touched by one of them, it instantly becomes motionless, and does not resume its activity for some time. The pulsations of the contractile vesicle are very regular, and its duty is the same as in the Amœba princeps.