THE CONVOLVULUS 
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brighter tints of that massy canopy which overhangs them. 
It is very evident that the ascending position of the 
greater number of plants is necessary both for their pros- 
perity and the welfare of man and the lower animals. 
How soon would the profuseness of vegetation become a 
curse rather than a blessing, if it were not for the pro- 
visions made for this ascending direction ! Were it not 
for this, the whole earth would be clogged with stems 
and foliage, and the industry of man could not effect a 
clearance for culture or pathway. At every step his foot 
would be entangled. Then indeed the woods would all 
be pathless, and the want of a free circulation of ak 
would render the plants coarse and rank, and destroy 
some of the most delicate among them. The vegetable 
matter would accumulate by their continual decay, and 
render the air impure ; while, as in the jungles of hot 
countries, the noxious reptile would lurk there unseen, and 
the wild animal would there lie down in his lair. 
One circumstance respecting twining plants is worthy of 
remark. Some of them follow the apparent course of the 
sun, and turn around the supporting stem, from left to 
right. This is the case with the common black bryony 
of our woods, which, with its shining heart-shaped leaves 
and small green flowers, may be seen in any wood during 
the summer months climbing over the trees. Other plants, 
as the large white bindweed or convolvulus, twine contrary 
to the sun, or from right to left. The peculiar tendency 
of the stem of every plant is always constant in each indi- 
vidual of the species. Thus, a large bindweed, wherever 
found, always turns one way, and a plant of black bryony 
the other; we never see its position reversed. Even if 
the gardener turn it in another direction, the plant, if 
unable to disengage itself and assume its natural bias, will 
eventually perish. 
The large white bindweed (Convolvulus sepium) is 
termed by recent botanists Calystegia sepium. It is very 
common about rivers, streams, or other moist grounds, 
and is a very graceful plant. The large white bells, which 
are called by country people “old man’s nightcap,” are 
exceeded by no blossoms in whiteness of tint or beauty of 
outline; and the leaves, which are heart-shaped, are very 
handsome. It often creeps over the drooping willow tree, 
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