Zoology : an elementary text-book / [Sir A.E. Shipley].

  • Arthur Shipley
Date:
1920
Catalogue details

Licence: Public Domain Mark

Credit: Zoology : an elementary text-book / [Sir A.E. Shipley]. Source: Wellcome Collection.

    40/780 (page 16)
    necessitate the use of a microscope for their examination. When magnified an Amoeba appears like a small, almost transparent lump of jelly, in which we can distinguish a thin outer rind and inner substance. The first, called the ectoplasm, is almost absolutely transparent, the second, called the endoplasm, has usually a grayish tinge, due to the presence of minute solid particles or granules, and is therefore described as granular. Often indeed, good sized objects of various shapes and generally of a green or yellow colour, can be seen in the endoplasm ; these are the undigested remains of the microscopic plants which the animal has Fig. 1. Avioeba proteus x 330. From Gruber. 1. Nucleus. 2. Contractile vacuole. 3. Pseudopodia, the dotted line points to the clear ectoplasm. 4. Food vacuoles. 5. Grains of sand. eaten and are surrounded by bubbles of water, termed food- vacuoles. Amoeba frequently engulfs particles of sand, though for what purpose is unknown; possibly in order to render itself less palatable to animals which might eat it. If the Amoeba is healthy we shall see it move. The transparent ectoplasm slowly sends out a projection, and then the granular endoplasm flows into it. As of course the size of the animal does not alter, when a process is thrust out in front, the rest of the animal must follow it by shrinking away behind. These projections are called by the awkward name of pseudo¬ podia (Gr. \]/€vSyj<s, false, ttoSlov, a little foot); the adjective