POLLEN. 
75 
imd rolling -within their scaly envelopes, fertilize the ovaries. A curious fact ig 
stated by an Italian writer, viz., that in places about forty miles distant grew two 
palm-trees, the one without stamens, the other without pistils ; neither of them 
bore seed for many years ; but in process of time they grew so tall as to tower 
above all the objects near them. The wind, thus meeting with no obstruction, 
waf*ed the pollen to the pistillate flowers, which, to the astonishment of ali, began 
to produce fruit. 
e. The number of plants in which the pistils and stamens are on different flowers 
is few compared to those which have these important organs inclosed within the 
same corolla ; as in our herbaceous pJants, and the trees of hot countries, whose 
leaves being always present might impede the passage of the pollen from other 
trees. On the contrary, the trees of cold climates have generally the stamens and 
pistils on separate flowers, blossoming before the leaves come forth, and in a windy 
season of the year. Those which blossom later, as the oak, are either peculiarly 
frequented by insects, or like the numerous kinds of firs, have leaves so httle in 
the way, and pollen so excessively abundant, that it can scarcely fail of gaining 
access to the pistillate flower. In all cases the pollen and stigma are in perfection 
at the same time ; in those flowers where the stamens and pistils are together, and 
of an equal length, some are drooping and some erect ; but where the stamens are 
longer than the pistil, the flower is usually erect ; where they are shorter, the 
flower is pendent : nature thus provides for the fertilization of the germ by tlie fall 
of the farina upon the stigma. 
Fig. 89, at A, repre- 
sents a monoecious flow- 
er of the genus Eu- 
Dhorbia.* In the cen- 
ler of the perianth, a, 
is the infertile flower, 
consisting of several 
double stamens, c c, up- 
on jointed filaments, dd; 
h is the fertile flower, 
with a petal-like stig- 
ma. At B, the same 
flower before blossom- 
ing is represented as 
cut vertically, to show 
its internal structure at 
this period. C shows 
the same flower after 
its fertihzation. Be- 
fore the maturity of 
the blossom the pistil was above the stamens, as seen at B. At the expansion oi 
the perianth it was below the stamens, as at A 6 ;— resuming its erect position, we 
see the pistil at C, its ovary having become a fruit filled with swelling seeds. 
In the laurel (Kalmia) the ten sta- 
mens are confined by their anthers in 
ten cavities of the five-parted, mono- 
petalous corolla. When the flower is 
mature, the anthers suddenly spring 
from their confinement, and scatter 
their pollen upon the stigma. 
Fig. 90, at A, represents the 
* Euphorbia illyrica.—Mivhel. 
Facts stated by an Italian writer— c. Trees of hot countries liave mostly stamens and pistils on th»< 
lame »;orc„'a— Trees of cold countries have the stamens and pistils on separate flowers— Methods bt 
whicn the objects of nature are accomplished- Explain Fig. 89— Explain Fig 
90. 
