Page:Popular Science Monthly Volume 26.djvu/830

810 world the fruits of his labors and researches in a work entitled "The Bee-Keeper's Handy-Book; or, Twenty-two Years' Experience in Queen-Rearing."

Another feature of present bee-culture, which is at once both largely the cause of its present advanced condition in this country and the best proof of its wide extension, is its periodical literature. Devoted wholly or partially to apiculture, we now have no less than three or four papers in Canada, and nearly a dozen in the United States. Among the latter is one weekly devoted exclusively to bee-culture. This is the "American Bee Journal," published in Chicago by Thomas G. Newman. Among the former is the "Canadian Bee Journal," a weekly, just commenced under the most favorable and promising auspices. It is edited and published by D. A. Jones, of Beeton, Ontario.

Since the hitherto great difficulty of successfully wintering bees in these climates has been nearly overcome by the application of science, bee-culture must, in the near future, become a great and profitable national industry in Canada and the United States.



HE doctrine of the cell, as the unit of vegetable and animal structure, has been constantly varying in its details since its first proposal by Schleiden in 1837 and Schwamm in 1839. It was at first held that the cell was a microscopic vesicle, globular in its typical form, bounded by a firm membranous wall, and inclosing fluid or semi-fluid contents. In its interior lay a smaller vesicle called the nucleus, which occasionally held a minute mass called the nucleolus. The cell-wall was believed to be its active constituent, which selected materials from the surrounding fluid for cell-nutrition, and set up physical and chemical changes within its contents. At a later date Goodsir and Barry maintained that the nucleus was the active agent in these processes, and that self-division of the nucleus was the source of cell-division. It was also perceived that a cell-wall was by no means always present, and Leydig defined a cell as "a little mass of soft substance inclosing a nucleus." A more important step of progress was made about 1861, when Von Mohl, Brücke, Max Schultze, Beale, and others, propounded their views upon the subject. Brücke pointed out that the contents of cells frequently displayed spontaneous movement and contractile power; and Max Schultze declared that sarcode—the contractile substance which forms a large part of the bodies of the lower animals—was homologous with the contents of actively growing cells. Von Mohl had proposed the term protoplasm to designate the