The mechanism and physiology of sex determination / by Richard Goldschmidt ; translated by William J. Dakin.

  • Goldschmidt, Richard, 1878-1958.
Date:
1923
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Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: The mechanism and physiology of sex determination / by Richard Goldschmidt ; translated by William J. Dakin. Source: Wellcome Collection.

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    INTRODUCTION. THE NATURE OF SEX в mortal. The rest of the organism commences its existence with the separation of the somatic cells from the germ cells and terminates with death. The physiological significance of this is that the cells of the body become exhausted through their functioning, and finally their existence as living cells must come to an end. In what way this is brought about does not concern us here. The fact, however, is clear. Thus the chief feature of the reproductive or sex cells, con¬ trasted with the cells of the rest of the body, is that they are not being used up physio¬ logically during the life of the individual. The somatic cells—muscle, nerve, and gland cells, for example—function¬ ing for the whole body, carry out work which through chemical limi¬ tations necessarily leads to death. The sex cells remain pro tected from these ma¬ lignant functions, they rest—sit venia verbo— physiologically vir¬ ginal, and are in a position therefore to survive the rest of the body in their descend¬ ants. For this reason the position of the sex cells in the body has often been compared to that of a parasite—not altogether a happy comparison. A better, perhaps, would be with the queen in a Termite colony ; she, whilst taking no active part in the working life of the colony, is supported by the workers, for the sole purpose of reproducing the following generations. This peculiar position of the sex cells in the body is revealed in their history. One of the most striking facts of animal embryology is the early separation of the germ cells ; it can be demonstrated in all the groups. The number of exceptions steadily diminishes and these Fig. i.—Eight segmentation stages of Ascaris megalo- ccphala, demonstrating chromatin diminut'on. S|, the primordial somatic cell; Р]-Рз, the stem cells of the germ cells ; S?, the second primordial somatic cell; Ej, ect Ectoderm anlage ; mst. Anlage of Mesoderm and Stomodaeum ; rk. polar body ; IIa, the chromosomes of the primitive somatic cell. After Boveri from Harms.