The development of the human body; a manual of human embryology . Fig. 18 18.—Four Stages in the Segmentation of the Blastodermof the Chick.—(Coste.) nutritive material is so great that the segmentation isconfined to the small yolkless disk of protoplasm andaffects consequently only a portion of the entire distinguish this form of segmentation from that whichaffects the entire ovum it is termed meroblastic segmenta-tion, the other form being known as 58 THE DEVELOPMENT OF THE HUMAN BODY. In the ovum of a turtle or a bird the first plane of seg-mentation crosses the protop
The development of the human body; a manual of human embryology . Fig. 18 18.—Four Stages in the Segmentation of the Blastodermof the Chick.—(Coste.) nutritive material is so great that the segmentation isconfined to the small yolkless disk of protoplasm andaffects consequently only a portion of the entire distinguish this form of segmentation from that whichaffects the entire ovum it is termed meroblastic segmenta-tion, the other form being known as 58 THE DEVELOPMENT OF THE HUMAN BODY. In the ovum of a turtle or a bird the first plane of seg-mentation crosses the protoplasmic disk, dividing it intotwo practically equal halves, and the second plane formsat approximately right angles to the first one, dividingthe disk into four quadrants (Fig. 18, A). The thirddivision, like the two which precede it, is radial in position,while the fourth is circular and cuts off the inner ends ofthe six cells previously formed (Fig. 18, D). The disknow consists of six central smaller cells surrounded by six
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
