. Botany for young people : Part II. How plants behave ; how they move, climb, employ insects to work for them, & c. Botany. 16 HOW i-LANTS 23. When, however, the fresh and active tendril comes in contact with a neighboring stalk, or any similar support, it hooks or coils its end round it; then, having secured a hold, it shortens by coiling up its whole length, or a good part of it. This commonly draws up the climbing stem nearer to its support, and makes it easier for the younger tendrils above to gain their hold. A tendril which has taken hold and coiled up usually becomes stoute
. Botany for young people : Part II. How plants behave ; how they move, climb, employ insects to work for them, & c. Botany. 16 HOW i-LANTS 23. When, however, the fresh and active tendril comes in contact with a neighboring stalk, or any similar support, it hooks or coils its end round it; then, having secured a hold, it shortens by coiling up its whole length, or a good part of it. This commonly draws up the climbing stem nearer to its support, and makes it easier for the younger tendrils above to gain their hold. A tendril which has taken hold and coiled up usually becomes stouter, rigid, and much stronger than it was before. One which would break with an ounce weight be- comes capable of supporting two or three pounds. 24:. There is a difference to be noticed be- tween the coiling of a free tendril and of one which has taken hold. It is plainly shown in Fig. 6. The loose tendril coils up, if at all, from the end, and in a simple spiral or curl. But when attached to a support, both ends be- ing fixed, it cannot coil in this way. It has to coil in the middle ; and the coihng of one part, say from right to left, requires another part to twist as much in the opposite direction. So the coil has a break in the middle, half twist- ing one way and half the other way, as is shown in the lower tendril of the figure. A longer tendril often has three or four, or even five or six, such breaks, the por- tions coiled successively in opposite directions. 26. Pumpkins, Squashes, and all the Gourd Family furnish excellent examples of these actions of tendrils. Their tendrils are like those of Passion-flowers, ex- cept that they are mostly branched or compound, and, like the claws of a bird, . stretch out in several directions. Fig. 6. Maple-leaved Passion-flower, witli ten- driU in TariouB Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1872
