. The cell; outlines of general anatomy and physiology. Fig. 114.—An egg ofAscaris nigrovenosa with four segments. (AfterAuerbach, PI. IV., ) lb. Unequal Segmentation. Unequal division comes naturally after equal. It is most-generally caused by the unequal distribution of the protoplasmand yolk substance in the cell. The Frogs egg, in which polardifferentiation has occurred, will serve as an example of , as has already been stated, the nucleus is situated in theupper or animal half of the sphere (p. 217). Now when divisionis about to occur, the axis can no longer lie in any on
. The cell; outlines of general anatomy and physiology. Fig. 114.—An egg ofAscaris nigrovenosa with four segments. (AfterAuerbach, PI. IV., ) lb. Unequal Segmentation. Unequal division comes naturally after equal. It is most-generally caused by the unequal distribution of the protoplasmand yolk substance in the cell. The Frogs egg, in which polardifferentiation has occurred, will serve as an example of , as has already been stated, the nucleus is situated in theupper or animal half of the sphere (p. 217). Now when divisionis about to occur, the axis can no longer lie in any one of of the egg, for, in consequence of the unequal division of theprotoplasm in the egg space, it is influenced by that part ofthe egg, which is pigmented and rich in protoplasm ; this portionrests like a skull-cap upon the more transparent deutoplasm-con- Q 226 THE CELL taining portion, and, on account of its smaller specific gravity,floats upwards, and is spread out horizontally (Fig. 115^4). The A B P ^m^ ^***± P -pv.
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