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defect arising from the wind being excluded, by taking the 
stamen and placing the dust on the stigma, and thus a 
cucumber is produced. As a still further illustration, the 
date has not only distinct flowers, some of which bear only 
stamens, and others only pistils, but has this further pecu- 
liarity, that no one of these trees bears both kinds of 
flowers. The Egyptians only cultivate the trees that have 
fruit-bearing flowers. Every year they send to Abyssinia, 
at the proper season, for branches covered with the other 
flowers and hang them up on their own date trees, and thus 
impregnation takes place. When the great Napoleon made 
his celebrated invasion, that people were so much engaged 
in defending themselves, that they neglected to fetch these 
branches of flowers as they had hitherto done. What was 
the consequence ? During that year there was not a single 
date in Egypt. Now Eerns are considered not-flowering 
plants, and therefore nothing like impregnation is supposed 
to happen to them. This seems strange, as some of them 
are very large, even magnificent forest trees. They also 
differ from most others belonging to this portion of the 
vegetable world in not having a cellular, but vascular tissue, 
and in possessing woody fibre. Hybrids, also, are occasion- 
ally produced. In flowering plants a hybrid is said to be 
formed by the pollen of one species falling on the stigma of 
another. Thus if a nurseryman has a choice turnip,* and 
wishes to save the seed of it, he is very careful that no other 
species of the genus should blossom near it, lest, as the 
common saying is, the bees should inoculate it, i.e, carry the 
powder or pollen of the one to the stigma of the other, and 
the seed would consequently produce a hybrid or inferior 
plant. If there are then hybrids in Ferns, and experienced 
gardeners maintain that there are, it is probable that 
something similar occurs to what happens in flowering 
plants. What seemed so likely, has been ascertained to be 
true by interesting experiments. There is, however, this 
difference, that in ordinary cases impregnation takes place 
before the fruit is formed, while in Ferns it is after the 
production of the spores. It appears that when the spores 
* This is mentioned because there are so many allied species, cabbages, charlock, 
&c., through which hybrids may be formed. 
