. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. A pocket germinator, in which the roots of the barley seedlings show a turning in response to gravity. The germinator was originally turned 180° from its present position. place on it some well- soaked radish or mustard seeds or grains of barley, and cover it with the other glass. The whole box thus made should be bound together with bi- cycle tape. Seeds will germinate in this box, and with care may live for two weeks or more. Influence of Gravity. — We are all familiar with the fact that
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. A pocket germinator, in which the roots of the barley seedlings show a turning in response to gravity. The germinator was originally turned 180° from its present position. place on it some well- soaked radish or mustard seeds or grains of barley, and cover it with the other glass. The whole box thus made should be bound together with bi- cycle tape. Seeds will germinate in this box, and with care may live for two weeks or more. Influence of Gravity. — We are all familiar with the fact that the force we call gravity influences life upon this earth to a great degree. Might gravity act on the growing root ? This question may be answered by the following simple experiment: Place your pocket garden on one edge and allow the seeds to germinate until the root has grown to a length of about half an inch. Then turn the box at right angles to the first position. Allow it to remain for one day ^_, undisturbed, and then examine it. The roots will be found to have turned in response to the change in position. In what part of the root does the change take place? What part of the growing root is most easily in- fluenced by the force of gravity? Make a series of drawings to illustrate this experi- ment. This experiment seems to indicate that the roots are influenced to grow downward by the force we call gravity. Experiments to determine Influence of Moisture on a Growing Root. — The objection might well be interposed that the roots in the pocket garden grew downward after water. This is unlikely, however, as the air in the germinator is saturated with moisture. That moisture has an influence on the growing root is easily Revolve this figure in the direc- tion of the arrows to see if the roots of the radish respond to gravity. Plant bird seed or the seed of mustard or radish in the under side of a sponge, which should be kept wet, and may be suspended by a string un
Size: 1346px × 1856px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookpublishernewyorkamericanbookcompany, booksubjectbiology
