64 
APPENDAGES TO PLANTS. 
in nature. A more rational opinion is given by another botanist, 
viz. — that thorns are in reality bulbs, which a more favourable situa 
tion converts into luxuriant branches. But in many cases, they ao 
not disappear even under circumstances the most favourable to ve- 
getation. Thorns have been compared to the horns of animals. 
4th. Glands are roundish, minute appendages, sometimes called 
tumours or swellings ; they contain a liquid secretion which is sup- 
posed to give to'-many plants their fragrance. They are sometimes 
attached to the base of the leaf, sometimes they occur in the sub- 
stance of leaves ; as in the lemon and myrtle, causing them to ap- 
pear dotted when held to the hght. They are found on the petioles 
of the passion-fiow^er, and between the teeth and divisions of the 
leaves of many plants. 
5th. Stings are hair-like substances, causing pain by an acrid li- 
quor, which is discharged upon their being compressed 5 they are 
"hollow, slender, and pointed, as in the nettle. 
6th. Scales are substances, in some respect resembling the coarse 
scales of a fish ; they are often green, sometimes coloured, and are 
found upon all parts of vegetables, as upon the roots of bulbous 
plants, and upon the stems and branches of ether plants. They are 
imbricated upon the calyxes of most of the compound flowers. Yoi? 
have seen in buds, how important the scales are, in protecting the 
embryo plant during the winter. Scale-like calyxes surround the 
flowers of grasses, under the name of glumes. Scales envelop and 
sustain the stamens and fruit of the pine, oak, chestnut, &c. 
7th. Tendrils^ or claspers, are thread-like ap- 
pendages, by v^hich weak stems attach themselves 
to other bodies for support; they usually rise from 
the branches, in some cases from the leaf, and 
rarely from the leaf-stalk or flower-stalk. You have 
here "the representation of a tendril. Tendrils are 
very important and characteristic appendages to 
many plants. In the trumpet-flower and ivy, the 
tendrils serve for roots, planting themselves into 
the bark of trees, or in the walls of buildings. In 
the cucumber and some other plants, tendrils serve 
both for sustenance and shade. Many of the papi- 
lionaceous, or pea-blossom plants, have twining 
tendrils, which wind to the right, and back again. 
Among vegetables which have tendrils, has been 
discovered that property, which some have called, 
the instinctive intelhgence of plants. A poetical 
botanist represents the tendrils of the gourd and 
cucumber, as, " creeping away in disgust from the 
fatty fibres of the neighbouring olive." The man- 
ner in which tendrils stretch themselves forward to 
grasp some substances, while they shrink from 
others, is indeed astonishing ; but instead of ima- 
gining that they have a preference for some, and a 
dislike for other objects, it is more philosophical to 
conclude that these effects arise from physical 
causes, which do not the less exist because we can 
not discover them. It has been ascertained by experiments, that the 
tendrils of the vine, and some other plants, recede from the hght, 
and seek opaque bodies. The lact with respect to leaves is directly 
the rev,erse of this, for they turn themselves round to seek the light. 
Glands— Stinps— Scales— Tendrils— Recede from the light. 
