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Hormones and Heredity by J. T. Cunningham
page 5 of 228 (02%)
ovum into the body.

Delage argues that if the egg contains the substances characteristic of
certain categories of cells of the organism it ought to be affected at the
same time as those cells and by the same agents. He thinks that the egg
only contains the substances or the arrangements characteristic of certain
general functions (nervous, muscular, perhaps glandular of divers kinds)
but without attribution to localised organs. In his view there is no
representation of parts or of functions in the ovum, but a simple
qualitative conformity of constitution between the egg and the categories
of cells which in the body are charged with the accomplishment of the
principal functions. Thus mutilations of organs formed of tissues
occurring also elsewhere in the body cannot be hereditary, but if the
organ affected contains the whole of a certain kind of tissue such as
liver, spleen, kidney, then the blood undergoes a qualitative modification
which reacts on the constitution of the egg.

Suppose the internal secretion of a gland (_e.g._ glucose for the liver,
glycolytic for the ferment for the pancreas) is the physiological excitant
for the gland. If the gland is removed in whole or in part the proportion
of its internal secretion in the blood will be diminished. Then the gland,
if the suppression is partial, will undergo a new diminution of activity
But in, the egg the specific substance of the gland will also be less
stimulated, and in the next generation a diminution of the gland may
result. Thus Delage states Massin found that partial removal of the liver
in rabbits had an inherited effect. In the case of excretory glands the
contrary will be the case, for their removal causes increase in the blood
of the exciting urea and uric acid.

The effects of disuse are similar to those of mutilations and of use vice
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