Abstract
LONDON. Royal Society, May 28.—R. J. Ludford: (1) Cell organs during secretion in the epididymis. The Golgi apparatus hypertrophies and assumes different forms, according to the degree of secretory activity. There occur nucleolar extrusions, nuclear budding, and a differential staining of the nucleolus, while the mitochondria increase in number at the onset of secretory activity, and decrease during the course of secretion. Variations observed in the secreting cells in different tubules of the epididymis are probably indicatory of variations in the degree of intensity of the secretory process. Secretory activity is maintained by the elimination of waste products, which is effected by nucleolar extrusions from the nucleus, and by amitosis followed fey the discharge of a nucleus and part of the cytoplasm into the lumen of the tubule. Reconstruction of exhausted cells also occurs during a resting phase, while cells completely worn out are replaced, principally by the basal cells. (2) Nuclear activity in tissue cultures. The nucleoli of fibroblasts of the rat's kidney perform during life slow amoeboid movements. Occasionally a nucleolus approaches the inner surface of the nuclear membrane, and part of it is discharged into the cytoplasm, where it disintegrates. Also, a portion of the nucleus itself may be budded off, persist for a time, and then diffuse into the ground cytoplasm. These processes probably represent phases in the normal metabolic activity of the cell.- J. Needham and Dorothy Needham: The hydrogen-ion concentration and the oxidation reduction potential of the cell interior: a micro-injection study. Subject to certain assumptions, the cell-interior of Amoeba proteus has a hydrogen-ion concentration of approximately PH 7-6, and an oxidation reduction potential of between yH 17 and 19.-F. W. R. Bram-bell: The oogenesis of the fowl (Gallus Bankiva). The Golgi apparatus, type I, of the oocyte is demonstrated for the first time. It is shown to surround the centrosphere. An intrusion into the oocyte of Golgi apparatus, type 2, from the follicle cells takes place. The former, and possibly the latter, break up into fine granules and become dispersed throughout the cell during oogenesis. These granules probably persist as such, and produce the Golgi apparatus of each embryonic cell by a process of condensation. The mitochondria increase in number in the oocyte and form the mitochondrial cloud. The transitory mitochondrial yolk-body differentiates in the middle of this cloud. At a certain stage between the third and sixth week after hatching, a number of oocytes in the ovary of the chick enter upon a period of precocious growth, exhibiting remarkable abnormality in behaviour of their cytoplasmic inclusions and finally becoming atretic. This may represent the final degeneration of the primordial germ-cells.
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Societies and Academies. Nature 115, 893–895 (1925). https://doi.org/10.1038/115893a0
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DOI: https://doi.org/10.1038/115893a0