. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 70 OVUM. The cicatricula of the unfecundated egg, such as is laid by fowls secluded from the cock, differs from that now described princi- pally in the absence of the marked dis- tinction between the central clear and the peripheral opaque part. The germinal ve- sicle, which to all appearance remains the same in the ovary till the yolk leaves the ovarian capsule, is now no longer to be seen; and the cicatricula is often marked irregularly throughout, but more especially towards the circumference, with clearer intervals,
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 70 OVUM. The cicatricula of the unfecundated egg, such as is laid by fowls secluded from the cock, differs from that now described princi- pally in the absence of the marked dis- tinction between the central clear and the peripheral opaque part. The germinal ve- sicle, which to all appearance remains the same in the ovary till the yolk leaves the ovarian capsule, is now no longer to be seen; and the cicatricula is often marked irregularly throughout, but more especially towards the circumference, with clearer intervals, or small irregular circular orjoval spaces, mingled with the opaque substance of the disc. I have, not, however, had the means in more recent times of making a sufficiently careful exami- nation of the cicatricula in this condition to enable me to state more minutely in what respects it differs from that of the fecundated egg- In the ovarian yolk, while still within its capsule, a white spot corresponding to the cicatricula also exists, and occupies the same place in relation to the yolk cavity and canal. Its structure and appearance, however, are somewhat different from that of the true cica- Fig. Cicatricula, and its contents, in the ovarian egg of the Fowl. A. A square portion of the surface of the ripe ovarian yolk, showing the vitelline disc or cicatricula, with the germinal vesicle in the centre, magnified ahout six diameters. u. Lateral view of the same, to show the con- vexity produced by the thickness of the disc round the germinal vesicle. c. Vertical diagrammatic section of the same; m, vitelline membrane; d, granular disc; g, germinal vesicle. D, E, F. Germinal vesicles more highly magnified; D, from a yolk of about one tenth of an inch dia- meter, showing scattered globules or germinal spots; E, from a nearly ripe 3-olk, quite clear; F, from another of the same period, exhibiting a turbid or minutely granular mass from the action of water. tricula of the egg
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