As caps between .15 and .2 of an inch in depth were thus proved to be
highly efficient in preventing the cotyledons from bending towards the
light, 8 other cotyledons were protected with caps between only .06 and .12
in depth. Of these, two remained vertical, one was considerably and five
slightly curved towards the light, but far less so than the free seedlings
in the same pots.
[page 474]
Another trial was made in a different manner, namely, by bandaging with
strips of tin-foil, about .2 in breadth, the upper part, but not the actual
summit, of eight moderately young seedlings a little over half an inch in
height. The summits and the basal parts were thus left fully exposed to a
lateral light during 8 h.; an upper intermediate zone being protected. With
four of these seedlings the summits were exposed for a length of .05 inch,
and in two of them this part became curved towards the light, but the whole
lower part remained quite upright; whereas the entire length of the other
two seedlings became slightly curved towards the light. The summits of the
four other seedlings were exposed for a length of .
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