Elements of histology / by E. Klein.

  • Edward Emanuel Klein
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Elements of histology / by E. Klein. Source: Wellcome Collection.

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    Elemei^ts of Histology. CHAPTEH 1. CELLS. 1. The ripe ovum (Fig. 1) of man and mammals is a minute spherical mass of a soft, gelatinous, trans- parent, granular looking substance, containing nume- rous minute particles—yolk globules. It is invested by a radially striated deli- cate membrane, called the zona pellucida. Inside this clump, and situated more or less excentrically, is a vesicle—the germinal vesicle —and inside this, one or more solid spots — the germinal spot or spots. The gela- tinous transparent substance of the ovum, containing a very large percentage of proteid material, is called Protoplasm. Before and immediately after fertilisa- tion, the protoplasm of the ovum shows distinct move- ment, consisting in contraction and expansion. These movements are spontaneous—i.e., not caused by any directly visible external influence. The diameter of the ripe ovum in man and domestic animals varies between and of an inch. But [before it ripens the ovum is considerably smaller—in B—1 Eig. 1.—Kipe Ovum of Cat. a, Zona pellucida; 6, germinal vesicle; c, protoplasm.
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