6 7 
Beer. — On Elaiop lasts. 
and elongated in form (Fig. 9). In favourable cases one can see that the 
faintly yellowish drops or granules of which it now chiefly consists are 
becoming detached from the periphery of the main body of the elaioplast, 
and that these drops or granules are gradually scattered through the cell 
cavity (Fig. 10). Here they deepen their yellow tint, and in association 
with the red pigment developed in the cell-sap they produce the yellow, 
orange, or red coloration of the mature corolla-hairs, according as the one 
or the other pigmenting material predominates (Fig. 11). 
The constituent plastids of these elaioplasts, therefore, undergo quite 
a similar series of changes as the chlorophyll grains in autumn leaves, which 
were first described in detail by Sachs in 1863 (10), or in ripening fruits, also 
studied by Sachs (1865). By the time the hairs are fully matured the 
elaioplast has entirely resolved itself into the scattered yellow pigment of 
the cell. 
The corolla-hairs are not the only place in which elaioplasts occur in 
Gaillardia. They are also to be found in the stigmatic hairs, or in the more 
internal cells of the stigma and of the style, in the vegetative cells of the 
anther, and in the cells of the young pappus (calyx). 
I sought for them in vain in the root-hairs or in the tissues of the root, 
in the leaf and the hairs which cover it, in the stem, and its clothing 
of hairs. 
After I had completed my observations on the elaioplasts in the 
corolla-hairs, and drawn from them the conclusions which I have expressed 
above, I received a beautiful confirmation of the correctness of these views 
from the study of the elaioplasts in the other floral regions of Gaillardia. 
In the cells of the connective of the young stamen, bodies occur which 
resemble the elaioplasts of the corolla-hairs in every respect except that 
they are coloured more or less deeply green. They are mostly spherical, 
although sometimes elongated in shape (Fig. 14). Moreover, in neighbouring 
cells of the connective we find every transition between deeply green bodies 
of this description, and others which are almost colourless and differ in no 
v/ay from the elaioplasts of the corolla-hairs. On the addition of Iodine 
solution the occurrence of starch within the green bodies is readily demon- 
strated (Fig. 12). After remaining in the Iodine solution for some hours 
these intensely black-stained bodies form a most conspicuous feature in the 
otherwise yellow cells. 
The appearance and reactions of these green bodies, no less than the 
transitions which occur between them and the ordinary elaioplasts, leave no 
doubt that they also are elaioplasts which contain chlorophyll, and which 
have retained the power of starch-formation. The cells of the young style 
and stigma also possess green, starch-producing elaioplasts. 
Another very interesting case of green elaioplasts is furnished by 
the cells of the flattened basal plates or wings of the young pappus. In 
