12 



THE MICROSCOPE AND ITS REVELATIONS. 



stance is received into one of the vacuoles of the endosarc (Fig. 287, F), 

 where it lies in the first instance surrounded by liquid; and its nutri- 

 tive portion is gradually converted into an undistinguishable gelatinous 

 mass, which becomes incorporated with the material of the sarcode-body, 

 as may be seen by the general diffusion of any coloring particles it may 



contain. Several vacuoles may 



FIG. 285. be thus occupied at one time by 



alimentary particles; frequently 

 four to eight are thus distin- 

 guishable, and occasionally ten 

 or twelve ; Ehrenberg, in one 

 instance, counted as many as six- 

 teen, which he describedas mul- 

 tiple stomachs. Whilst the di- 

 gestive process, which usually 

 occupies some hours, is going on, 

 a kind of slow circulation takes 

 place in the entire mass of the 

 endosarc with its included va- 

 cuoles. If, as often happens, the 

 body taken-in as food possesses 

 some hard indigestible portion 

 (as the shell of an Entomostra- 

 can or Rotifer), this, after the 



Acti^kn^in different states:-,, in itsordin- di g e , Sti n f S ft ****>.* 

 arysun-likeform, with a prominent contractile vesi- gradually pushed towards the 

 cle o ; B, in the act of division or of conjugation, with Hnr fape nr ,H ; c fVcmna ovfrnrlorl 

 two contractile vesicles o, o ; c, in the act of feeding; f lace, anc 

 D, in the act of discharging faecal (?) matters, a and b. by a process exactly the Converse 



of that by which it was drawn 



in. If the particle be large, it usually escapes at once by an opening 

 which (like the mouth) extemporizes itself for the occasion (D); but, if 

 small, it sometimes glides along a pseudopodium from its base to its 

 point, and escapes from its extremity. 



400. The ordinary mode of Reproduction in Actinovhrys seems to be 

 by binary subdivision: its spherical body showing an "annular constric- 

 tion, which gradually deepens so as to separate its two halves by a sort 

 of hour-glass contraction; and the connecting band becoming more and 

 more slender, until the two halves are completely separated. This pro- 

 cess of fission, which may be completed within half an hour from its 

 commencement, seems to take place first in the contractile vesicle; for 

 each segment very early shows itself to be provided with its own (B, 0, 

 o), and the two vesicles are commonly removed to a considerable distance 

 from one another. The segments thus divided are not always equal, and 

 sometimes their difference in size is very considerable. A junction of 

 two individuals, on the other hand, has been seen to take place in Actino- 

 phrys, and has been supposed to correspond to the ' conjugation ' of Pro- 

 tophytes; it is very doubtful, however, whether this junction really in- 

 volves a complete fusion of the substance of the bodies which take part 

 in it; and there is not sufficient evidence that it has any true generative 

 character. Certain it is that such a junction or ' zygosis ' may take place, 

 not between two only, but between several individuals at once, their 

 number being recognized by that of their contractile vesicles; and that, 

 after remaining thus united for several hours, they may separate again 

 without having undergone any discoverable change. 



