STRUCTURE OF LIVING THINGS 



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liquid matter, intermixed like an emulsion. It often has 

 within it large cavities filled with liquid, and also often 



B 



FIG. 36. Simple "cells," consisting of naked protoplasm, changing shape 

 and taking in solid food particles. A, is a series of four successive changes 

 of shape of a fresh-water animalcule, the proteus or amoeba ; B, is a 

 similar series of three views of a separate creeping kind of corpuscle 

 found in the blood and lymph-spaces of animals, and called a " phago- 

 cyte." It is also said to be " amoeboid," from its resemblance to the 

 amoeba or proteus-animalcule. B, is from the blood of the guinea-pig. 

 It is not a parasite, but one of the various kinds of cells which build up 

 the animal body, and are derived from the single original egg-cell (see 

 Fig. 3 1 ) by continued division. The three drawings show three changes 

 of shape occurring in the same "phagocyte" in a few minutes. It is 

 engulphing a fever-producing blood-parasite, a spirillum, marked a, 

 into its soft, slimy protoplasm, to be there digested and destroyed. In 

 the same way the amoeba, A, is seen in four stages of engulphing the 

 vegetable particle, a. In the fourth figure the letter b points to water 

 taken into the amoeba's protoplasm with the food-particle a. In all the 

 figures, c points to the " vacuole" or liquid-holding cavity, which bursts 

 and re-forms in A ; the letter d points to the cell-nucleus. 



oil drops ; in other cases hard concretions or coarse 

 granules. But apart from other things, the protoplasm 



