Abstract
An attempt has been made to review critically the physiological changes in cells with age. Several tentative generalizations may be made: ageing appears after growth stops; an ovum from an old individual has potentialities different from those of a young individual; the capacity for cell growth decreases with age; cytoplasmic pigments frequently increase with age and may be related to mitochondrial changes; and data on endocrine changes and cellular chemical changes are at present too scanty to warrant summary.
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