. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. Winged Seeds. — The seeds of the pine, held underneath the scales of the cone, are prolonged into wings, which aid in their dispersal. Tumble Weeds. — Sometimes whole plants are carried by the high winds of the fall. This is effected in the plants called tumble weeds, in which the plant body, as it dries, assumes a somewhat spherical shape. The main stalk breaks off and the plant may then be blown along the ground, scattering seeds as it goes, until it is ulti- mately stopped by a fence or
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. Winged Seeds. — The seeds of the pine, held underneath the scales of the cone, are prolonged into wings, which aid in their dispersal. Tumble Weeds. — Sometimes whole plants are carried by the high winds of the fall. This is effected in the plants called tumble weeds, in which the plant body, as it dries, assumes a somewhat spherical shape. The main stalk breaks off and the plant may then be blown along the ground, scattering seeds as it goes, until it is ulti- mately stopped by a fence or bush. A single plant of Rus- sian thistle may thus scatter over two hundred thousand seeds. Seeds or fruits (for exam- ple, the cocoanut) may fall into the water and be carried thousands of miles to their new resting-place, the fibrous husk providing a boat in which the seed is carried. The great Eng- lish naturalist, Charles Darwin, raised eighty-two plants from seeds carried in a ball of earth attached to the foot of a bird. It is probable that by means of birds and water most of the vegetation has come into existence on the newly formed coral islands of the Pacific Ocean. Some seeds have especial adaptations in the way of spines or projections. Insects make use of these projections in order to carry them away. Ants plant seeds which they have carried to their nests for a food supply. Nuts are planted in much the same manner by squirrels. Explosive Fruits. — Some fruits scatter their seeds through the explosion of the seed case. Such a fruit is the witch-hazel, which explodes with such force that the seeds are thrown several feet. The wild geranium, a five-loculed cap- Cross section of a cocoanut in its fibrous Pod of crane's bill discharg- ing its 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 may not perfectly resemble the origin
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Keywords: ., boo, bookpublishernewyorkamericanbookcompany, booksubjectbiology
