The individual
strength of the whole plant may still be affected in a more or less
manifest degree, but the number of converted stamens of the flower has
been definitely fixed. The sensitive period has terminated.
In order to determine the exact moment of this termination of the period
of sensibility, I have followed the development of the flower buds
during the first weeks of the life of the young plants. The terminal
flower may already be seen in young plants only seven weeks old, with a
stem not exceeding 5-6 cm. in height and a flower-bud with a diameter of
nearly 1 mm., in which the stamens and secondary pistils are already
discernible, but still in the condition of small rounded protuberances
on the thalamus. Though it is not possible at that time to observe any
difference between the future normal and converted stamens, it does not
seem doubtful that the development is so far advanced, that in the inner
tissues the decision has already definitely been taken. In the next few
days this decision rapidly becomes visible, and the different parts of
the normal stamens and the metamorphosed carpels soon become apparent.
From this observation it [386] can be inferred that the sensitive period
of the anomaly is limited for the terminal flower-head, to the first few
weeks of the life of the young plants.
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