ee 
fleshy fruits, cannot disseminate themselves 5 they 
388 PRINCIPLES OF BOTANY, ETC. 
of the Crataegus torminalis are conveyed ' far by our 
rivers. Many German plants are found on the 
shores of Sweden. Several Spanish and French 
plants on those of Great Britain ; many African 
and Asiatic plants are met with on the coasts of Italy : 
The wind likewise carries those seeds which are pre- 
yided with a pappus, with wings, or with mem- 
braneous margins, as well as the capsules of seeds 
extended by air, that they may germinate in far 
distant places. For this reason several plants which 
possess very light seeds, have been far disseminated 
in the very | direction the wind had mostly blown, 
and to greater extent, than it would have happened 
witioue’ the aid of the wind. The winged seeds ‘ 
the birch, (Betula alba), are often carried by win 
to the top of high steeples, and the lofty summits 
of rocks, where they not unfrequently germinate. 
The birch, therefore, on account of the lightness of 
its seeds, is disseminated all over the north of Asia, 
where the heavy : seeds of the oak, (ouaians robur), 
cannot follow. | 
“Some seed capsules and fruits burst with a degree 
of elasticity which forces the seed round to some 
distance, whereas others, on the contrary, can only 
remain in the neighbourhood of their original abode, 
especially all those that ripen un ider eround, The 
pistil of some plants sinks after cite" blooming is 
over, into the ground, and there attains its maturity ; 
instances of this are, Arachis hypogaea ; Glycine ae. 
terranea ; ; Trifolium subterr ameum ; Lathyrus amphi- 
carpos ; Vicia subterranea. Berries s, and all the more 
fall 
