FOOD AND FEEDING. 469 



water under the field of a microscope, collides accidentally with an- 

 other jelly-speck who happens to be traveling in the opposite direction 

 across the same miniature ocean What thereupon occurs ? One 

 jelly-speck rolls itself gradually into the other, so that, instead of two, 

 there is now one ; and the united body proceeds to float away quite 

 unconcernedly, without waiting to trouble itself for a second with the 

 profound metaphysical question, which half of it is the original per- 

 sonality, and which half the devoured and digested. In these minute 

 and very simple animals there is absolutely no division of labor be- 

 tween part and part ; every bit of the jelly-like mass is alike head and 

 foot and mouth and stomach. The jelly-speck has no permanent limbs, 

 but it keeps putting forth vague arms and legs every now and then from 

 one side or the other ; and with these temporary and ever-dissolving 

 members it crawls along merrily through its tiny drop of stagnant 

 water. If two of the legs or arms happen to knock up casually against 

 one another, they coalesce at once, just like two drops of water on a 

 window-pane, or two strings of treacle slowly spreading along the sur- 

 face of a plate. When the jelly-speck meets any edible thing — a bit of 

 dead plant, a wee creature like itself, a microscopic Q^'g — it proceeds to 

 fold its own substance slimily around it, making, as it were, a tempo- 

 rary mouth for the purpose of swallowing it, and a temporary stom- 

 ach for the purpose of quietly digesting and assimilating it afterward. 

 Thus what at one moment is a foot may at the next moment become 

 a mouth, and at the moment after that again a rudimentary stomach. 

 The animal has no skin and no body, no outside and no inside, no dis- 

 tinction of parts or members, no individuality, no identity. Roll it 

 up into one with another of its kind, and it couldn't tell you itself a 

 minute afterward which of the two it had really been a minute before. 

 The question of personal identity is here considerably mixed. 



But as soon as we get to rather larger creatures of the same type, 

 the antithesis between the eater and the eaten begins to assume a 

 more definite character. The big jelly-bag approaches a good many 

 smaller jelly-bags, microscopic plants, and other appropriate food- 

 stuffs, and, surrounding them rapidly with its crawling arms, envel- 

 ops them in its own substance, which closes behind them and gradually 

 digests them. Everybody knows, by name at least, that revolutionary 

 and evolutionary hero, the amceba — the terror of theologians, the pet 

 of professors, and the insufferable bore of the general reader. Well, 

 this parlous and subversive little animal consists of a comparatively 

 large mass of soft jelly, pushing forth slender lobes, like threads or 

 fingers, from its own substance, and gliding about, by means of these 

 tiny legs, over water-plants and other submerged surfaces. But though 

 it can literally turn itself inside out, like a glove, it still has some faint 

 beginnings of a mouth and stomach, for it generally takes in food and 

 absorbs water through a particular part of its surface, where the 

 slimy mass of its body is thinnest. Thus the amoeba may be said 



