Amœba

Proteus animalcule, so called because its form of body is always changing, owing to the fact that pseudopodia are formed and retracted at will from any part of the surface. It is a naked rhizopod and reprèsents a single cell, having a clear, firm ectosare and a fluid, granular endosare, with a nucleus imbedded in the former. It multiplies by simple division, which is preceded by division of the nucleus, so that each daughter amœba is nucleated from the start. This IMG:content-0157.jpg:[graphic] Amœba proteus. animal eats by simply allowing its food (which is vegetable, sometimes algæ, sometimes bacteria, etc.) to sink into the substance of its body or by inclosing it with its protoplasmic pseudopods. Then the albuminous parts are digested out, and a imilated by being converted into a part of the protoplasm of the amœba, while the indigestible cellusose wall and starchy contents are ejected from whatever part of the body happens to be hindmost. When moving, it causes a part of its substance to flow out in any direction (forming a pseudopod), and the rest of the body flows into this pseudopod, swelling it up and converting it into the body of the ameba. There seem to be no organs, no nerves, no stomach, etc., present; yet the animal can perceive the presence of food, can travel, digest, reproduce, succe fully maintain itself, and do all that protoplasm in any animal can do. It can be killed or destroyed, but never dies of old age. It simply grows, and then multiplies by splitting into two halves, which are young amœbæ.