78 
STAMENS AND PISTILS. 
fied. Fig. 83, A, shows the 
pistil of the Cynoglossum. 
The style iscylindric; stig- 
ma depressed or flattened at 
the top. Four ovaries or ru- 
diments of seeds. 
B, sho¥/s the pistil of the 
Tournefortii. The stigma 
is hemispherical, sub-ses- 
sile, surrounded with a 
r/z glandular hood, a. C, shows 
the pistil of the Hehtropi- 
um : a, four ovaries, two of 
which only are visible in the 
cut ; b, a short style ; c, a 
conical, four-parted stig- 
ma. 
D, shows a pistil of the genus Cucumis 5 a, is the ovary adhering to 
the calyx ; b, three abortive stamens ; c, cylindric style ; d, three- 
lobed stigmas. 
E, pistil of the Rum ex genus ; a, a, plumose stigmas. 
Use of the Stamens and Pistils. 
In a former part of our Lectures, it was observed that the stamens 
and pistils were necessary to the perfection of the fruit ; we will 
now explain to you the manner in which they conduce to this impor- 
tant object ; as you are now acquainted with the different organs 
and their names, you are prepared to understand the explanation. 
The pollen, which, in most flowers, is a kind of farina, or yellow 
dust, is thrown out by the bursting of the anther, which takes place 
in a certain stage of the flower. The pollen is very curiously form- 
ed ; although appearing like little particles of dust, upon examining 
it with a microscope it is found to be composed of innumerable or- 
ganized corpuscles.* These little bodies, though usually yellow, are 
sometimes white, red, blue, &c. In order to observe them w^ell, it is 
necessary to put them upon water ; the moisture, by swelling them, 
renders their true form perceptible. They are oblong in the Um- 
belliferous plants, globular in the Syngenesious, and triangular in 
some others. In some their surface is smooth, in others armed with 
little points. They are connected together by minute threads, as in 
the honeysuckle, &c. These particles of pollen thus placed upon 
water, swell with the moisture until they burst; a liquid matter is then 
thrown out, and, expanding upon the surface of the water, appears 
like a light cloud. 
The figure represents the pollen of seve- 
ral different kinds of plants as seen under 
a magnifier, when placed upon water. At 
a, is a grain of pollen of one of the Mal- 
^ lows-like plants, it is globular, hispid. At 
^«?f!^ ^ ^ b, the grain of the pollen is four-lobed. 
This belongs to the Orchis family. At c, is 
the pollen of the Aster. At d, is the pollen 
of the Hibiscus, globular, muricated. At c, 
is the pollen of the Nasturtium ; angular. At f, is the pollen of the 
honeysuckle. 
* Little bodies or particles of matter. 
Explain Fig. 83— Use of the stamens and pistils— Description of the pollen. 
