Upon the inheritance of acquired characters : a hypothesis of heredity, development, and assimilation / Eugenio Rignano ; authorized English translation by Basil C.H. Harvey.

  • Eugenio Rignano
Date:
1911
Catalogue details

Licence: In copyright

Credit: Upon the inheritance of acquired characters : a hypothesis of heredity, development, and assimilation / Eugenio Rignano ; authorized English translation by Basil C.H. Harvey. Source: Wellcome Collection.

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    germinai substance, and one suspects at once that it may be just this substance which constitutes thè centrai zone. If so it would follow that thè centrai zone must be at thè same time thè germinative zone, that is to say, thè place whence thè sexual cells get thè germinai substance which makes them capable of reproduction. Let us hasten to add now that thè centrai zone must coincide with thè effective germinai zone, but may possibly be quite separate and distinct from thè apparent germinai zone. The latter would be then only thè place of formation of thè sexual cells, inasmuch as these constitute in a certain sense thè mere envelope in which later thè germinai sub- stance is assembled, which alone is able to give them reproductive capacity. The hypothesis of centroepigenesis includes then that of a continuous action exercised by thè germinai sub- stance upon thè soma throughout thè whole duratimi of its development. We shall endeavor in thè second chapter to learn what is thè nature of this action and we shall reserve for consideration in thè third chapter thè centrai zone itself, as well as other facts and arguments which make its existence seem probable and which serve to make thè hypothesis clearer. We shall limit ourselves here to putting in special light thè fundamental characteristics which differentiate this hypothesis as well from thè preformistic as from thè epigenetic theories. While Weismann and thè preformists in generai con- sider that thè germ plasm separates itself before thè com- mencement of development from thè portion set apart to form thè new organism, and remains passively aside in a detached part of thè soma until it later steps in to form thè future sexual cells; consequently it would not control
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