Page:Popular Science Monthly Volume 6.djvu/363

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BIOLOGY FOR YOUNG BEGINNERS.
349

that are smaller than the amœba itself (Fig. 24). These it feeds upon, and, if you have patience to look long enough, you can see how it eats. It has no mouth in particular—the feet seem to taste of what-ever comes in their way, and, if they like it, they grasp it, and poke it in anywhere into the middle of the jelly or protoplasm (Fig. 25).

Fig. 24.—Pond Amœba digesting its Food. Fig. 25.—Amœba eating.

Here it is digested, and all parts that cannot be used are pushed out again. All that the amœba has to do is to swallow the mass, suck out all the meat, and throw the rest away. There is one thing you must remember about the amœba; it must have its food or protein ready made. It has no power like the yeast or protococcus cell to make it for itself. So these little jelly-lumps we find in the blood and the ponds must be animals. You remember, I told you all vegetables make protein, while all animals eat it up. This little amœba animal gets its full share. He is a perfect little gourmand, taking in every thing that comes in his way. The human amœbae are more fastidious in their taste. They do not swallow their food whole like the wild amœbæ. But those that are found in the blood of the newt or frog are regular little cannibals, and eat up their "colored brethren" whenever they get the chance.

Then, too, the feet or pseudopodia of the savage tribe are thicker and shorter than feet of the civilized kind. You see the toes of your amœba are quite dainty and tapering, like a lady's fingers. It is very curious to watch how a pseudopodium is made, especially of the pond amœba. First there is a little swelling or lifting up of the glassy

Fig. 26.—Wild Amœba. Fig. 27.—Human Amœba. Fig. 28.—Amœba making a Foot.

rim or outer flesh (Fig. 28). As this swelling gets larger, some of the inner flesh flows into it, carrying the little grains, till the swelling is all filled up (Fig. 29).

Then the walking is so funny! The feet do not act as the feet of other animals, carrying the body above them. First, one stumpy foot