Page:Popular Science Monthly Volume 90.djvu/105

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��Different stages in the division of the protozoan

��Popular Science Monthly

Mr. George E. Stone, of Berkeley, California, has hit upon the idea of applying this principle to make clear the complex subject of life and the methods by which plants and animals are born, live and die. With the assistance of Dr. J. A. Long, Professor of Embryology- in the Universit}^ of California, a film has been prepared which not only surpasses anything that has hitherto been attempted in showing the blossoming of flowers, but which is of immense scientific importance as well. No doubt other scientific men have had the same idea. But for lack of a suitable apparatus they were unable to photograph the minute life which is seen only through the microscope. This, Mr. Stone has invented. Some of the remarkable films which he has obtained are reproduced in connection with this article.

Simple Cells Merely Split in Two The simplest plant or animal is that which consists of but one cell. Hence his film starts its photographic lesson in "How Life Begins" by showing a swarming mass of protozoans — simplest of all animals, because their bodies consist of but a single cell each. A protozoan reproduces its own kind by the simple process of splitting itself up into two parts. That fact the film drives home very clearh^ A protozoan, highly magnified, is obser\-ed to constrict and divide in the middle. Each of the halves thus formed at once becomes a new one-cell creature. And each of these new creatures, in turn, splits up into new cells, until thev become so numerous that at last one realizes

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���In making motion pictures of microscopic life, Mr. Stone used the electric arc. The camera was driven by an electric motor controlled by the foot

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��It was a three weeks' task to take this strip of fJm

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��New protozoans resulting from a division of an or- iginal protozoan

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