i8 4 POPULAR SCIENCE MONTHLY. 



in the course of a minute or two,* so that we should have, as it were, 

 a greatly magnified representation of the movements involved in 

 plant growth. If, for example, our pictures were taken at half- 

 hourly intervals, and shown at a speed of fifty per second, the ap- 

 parent rate of growth of the plant would be increased no less than 

 ninety thousand times. A slower rate would evidently correspond 

 to a diminished time interval between successive negatives; and this 

 interval should in all cases be so chosen as to insure gradual (though 

 distinctly perceptible) changes in the resulting pictures. 



Such views could not fail to produce an effect at once mar- 

 velous, unique, and instructive. As pictured upon the canvas, the 

 plants would grow and develop before the eyes of onlookers, throw- 

 ing out leaf upon leaf, and visibly increasing their dimensions. 

 Here and there a flower or flower cluster might make its appearance, 

 the individual blossoms bursting forth suddenly and remaining visi- 

 ble for a brief period only. The process is clearly applicable to 

 greenhouse or indoor plants of every description, from stately palms 

 or tree ferns down to the most delicate mosses or lichens. Thus, the 

 general phenomena of plant growth may be illustrated with a vivid- 

 ness never before realized. As object lessons in botany, such motion 

 pictures would be invaluable, while the general public, not less than 

 the advanced student of science, would regard them with feelings of 

 the keenest interest. 



Instead of photographing an entire plant, we might direct our 

 efforts to the representation of its more interesting details. Thus, 

 an expanding leaf bud or a flower stalk would furnish highly at- 

 tractive views for the cinematograph. The microscope, too, could 

 be brought to bear, and with its aid we should be enabled to depict 

 the more delicate and subtle processes of vegetable growth. Such 

 optical studies would be not merely instructive in the ordinary sense 

 of that term, but they would be likely to throw new light on bio- 

 logical problems of the deepest interest. For we are here concerned 

 with changes which can not be directly observed, and whose nature 

 can only be imperfectly apprehended from a comparison of ordinary 

 photographs taken for the purpose. "We know, for example, that 

 common instantaneous views of men or animals in motion convey a 

 most imperfect idea of the actual movements involved in walking 

 or running; and a similar remark would doubtless apply with 

 greater force in cases where the pictured objects were undergoing 

 changes of a complex physical nature; so that the human eye, 

 aided by the sensation* of motion, might well succeed in bringing to 

 light laws or relations hitherto unrecognized by botanists. 



* Although the motion views do not commonly endure beyond these limits, it should be 

 noted that a much longer duration — involving the use of many films — is now practicable. 



