THE MICROSCOPE. Dik 
by its five segments. (b represents one of the segments, 
natural size.) The stigma is a bundle of papillee, and is placed, as 
mentioned above, in the recess formed by the segments at their 
point of meeting. The conducting tissue runs down from the 
stigma along the ribs of the pistil. Its five branches meet at the 
apex of the style surmounting the ovary. The conducting tissue is 
easily separated from the pistil (b), and under the microscope 
presents a finely-fibrillated tissue, bearing numberless granules 
and blotches of the contents of the pollen taken up by the 
stigma. The anthers are hypogynous and numerous. The conduct- 
ing tissue is coexisting with the other organs of a plant. It is 
developing along with them, and is found everywhere it has 
hereafter to perform an office. Prior to the maturity of the anther, 
which is reached at quite an early period of plant life, and before 
the pollen has been deposited on the stigma, the conducting tissue 
presents also a fibrillated appearance, minus the granules, which 
appear only after the pollen has been deposited on the stigma. The 
five branches of the conducting tissue unite at the apex of the style, 
and after having been charged on the stigma with the fertilizing 
element of the pollen, descend through the style into the interior of 
the ovary, fertilizing it as a whole. The anatropous ovules are 
brought by their micropyle in contact with the placente. The 
fertilizing fluid contained therein is taken up by the papilla around 
the micropyle, and thereby brought in contact with the oosphere in 
the embryo sac. Fertilization is now accomplished. 
The advocates of the pollen-tube theory maintain that the 
pollen-tubes, which, after the pollen has come in contact with the 
viscid matter on the stigma, are emitted sometimes, carry on their 
apex, as already menticned above, a vegetative and a gen- 
erative nucleus. These tubes are supposed to  vegetate 
and lengthen in the midst of the connecting tissue as they are 
progressing in their route towards the micropyle and the oosphere 
in the embryo sac; therefore, in the present instance, the pollen-tube 
would have to travel from the stigma along the ribs of the five 
segments of the minute style at the apex of the ovary. Here the 
first difficulty would present itself. The style is only about ,', inch 
in diameter; each ovule must be accorded a separate tube; the 
descent through the tissues of the style of more than one or two is 
an impossibility. Should this difficulty, however, have been over- 
come, another and still greater one presents itself in the cavity of 
ovary. (c.) Here the placentze are parietal; the ovules are 
anatropous, the micropyle is in close contact with the tissues of the 
