428 EVENINGS AT THE MICROSCOPE 



to impart a visible tinge to it, and close the live-box 

 again. Already you perceive that some of the tiny glob- 

 ules are become turbid and red, and that their opacity and 

 color are deepening perceptibly. "We see by this that the 

 particles of carmine have been taken into the jelly-like 

 sarcode, and are accumulating in little pellets surrounded 

 by fluid, in these casual hollows of its substance. The 

 process is rendered still more obvious when, as is often 

 the case, some Diatomacean, with a hard siliceous shell, 

 becomes the food of the Amoeba. The apparently helpless 

 jelly spreads itself over the organism, so as soon to en- 

 velop it; the Hesh, which having no skin can unite with 

 itself wherever the parts come into contact, closes over the 

 Diatom, which is thus brought into the midst of the sar- 

 code, a vacuole being new-made for its reception. This, 

 then, performs the part of a temporary stomach, the di- 

 gestible portions of the prey are extracted, and then the 

 insoluble shell of flint is, as it were, gradually squeezed 

 to some part of the exterior, and gradually forced out, the 

 vacuole disappearing with it, or perhaps retaining a mi- 

 nute portion of the fluid, and thus perpetuating itself for 

 a while. This is the earliest condition in which the proc- 

 ess of digestion can be recognized. 



Another genus somewhat similar is Arcetta, but it dif- 

 fers in being furnished with a more or less rounded shell 

 (lorica), like a little box. In examining the matters that 

 adhere to the stems of Duckweed, and other water plants, 

 we frequently observe little circular bodies of a yellowish 

 or reddish brown color, some much darker than others, 

 but all having a central round spot paler than the rest. 

 On first examination they seem inert and dead, but if we 

 closely watch one, we perceive that it is endowed with the 



