FEKTILIZATION IN PLANTS. 
435 
of the corolla^ but are concealed within it. The pollen, in 
both sets of stamens, is yellow, and the grains are a little 
larger in the long than in the short stamens. In size, the 
seeds of this form were larger than in either of the others, 
so that five seeds of the long-styled form were equal to six of 
the mid-styled form and seven of the short-styled form. 
In the mid-styled form (b), the pistil was shorter than the 
six long stamens and longer than the six short stamens, but 
it extended beyond the mouth of the corolla. The six short 
stamens, as in the long-styled form, did not extend beyond 
the corolla. The six longer stamens had pink filaments, and 
corresponded in length with the pistil in the long- styled form, 
whilst the six long stamens, in the long- styled form, corre- 
sponded with the pistil in the mid-styled form. The pollen 
grains of the long stamens in this form were greenish, whilst 
those of the short stamens were yellow. 
In the short-styled form (c), the pistil was very short, not 
extending to the mouth of the corolla, and in length equalling 
the set of short stamens in each of the preceding forms. The 
long stamens were of equal length to the long stamens in the 
mid-styled form and the pistil in the long-styled form, whilst 
the short stamens were equal to the long stamens in the long- 
styled form and the pistil in the mid-styled form. In this 
form all the stamens extended beyond the mouth of the 
corolla. The filaments of the longer stamens were pink and 
the pollen greenish, as in the long stamens of the mid-styled 
form, whilst in their uncoloured filaments and yellow pollen 
as .well as in length, the six shorter stamens corresponded 
with the long stamens in the long-styled form. All the pistils 
and stamens, in all three forms, were bent upwards towards 
their extremities, in a manner corresponding with their 
length. Hence it will be observed, that there are three distinct 
female organs, differing in length, curvature, and in the size 
of the seed. That there are three kinds of stamens : short — • 
with white filaments and yellow pollen ; medium — with white 
filaments and yellow pollen ; long — with pink filaments and 
greenish pollen. 
We cannot enter into the more minute particulars of Mr. 
DarwiAs communication, suffice it to say, that from careful 
experiment he ascertained what the greatest amount of fertility 
was produced by the union of pollen borne on filaments of an 
equal length with the pistils fertilized ; that is, from the 
shortest stamens with the shortest pistil, from the longest 
stamens with the longest pistil, and from the medium stamens 
with the medium pistil. In all three forms the female organ 
was but feebly, if at all, influenced by the two kinds of pollen 
produced in the same flower. So that of eighteen possible 
VOL. IV. — NO. XVI. 2 G 
