(a) . The Division Period. Oogonia and Spermatogonia
(b) . The Growth Period. Oocytes and Spermatocytes
(c). The Maturation Period
4. Sex Determination
EDWIN GRANT CONKLIN
HEREDITY is to-day the central problem of biology. This problem may be approached from many sides—that of the observer, the statistician, the practical breeder, the experimenter, the embryologist, the cytologist—but these different aspects of the subject may be reduced to three general methods of study, (1) the observational and statistical, (2) the experimental, (3) the cytologica! and embryological.
THE origin of all nitrate deposits was at one time accounted for by oxidation. The theory was held that the production of nascent nitrogen through the decomposition of organic matter caused a union to take place between the oxygen of the air and the nitrogen of the organic matter.
THERE are many factors which influence international relations. Among the most important are language, culture, religion and commerce. If the peoples of two countries speak the same language intercourse between them is much easier and sympathetic relations are likely to exist between them.
OUR tastes in pictures do not tíy any means agree—even those of very wise critics, who ought to know the good from the bad. "We might get into all sorts of difficulties with the words good and bad ; but most of us look at pictures because we enjoy them, and our varying choices have some elements in common. These common factors are a sort of minimum wage which we ask in return for our attention, and our pay must be immediately convertible into pleasure.
THE science of apiculture, as it is understood to-day, is the slow growth of centuries of human observation and investigation. For unnumbered ages it has been a work of interest to man to reclaim these singularly untamable insects from the state ferœ naturae to that domites natures, as the legal phrase has it—to render their natures sufficiently tractable to enable man to appropriate to himself the benefits of their toil.
THE food problem is distinctly a modern one in the United States. Two generations ago no such problem was clearly recognized. Fish were plentiful; pigeons, deer, wild turkeys, water-fowl, quail and buffalo were abundant; wild berries, fruits and nuts could be obtained easily and in large quantities.
THIS president has been reading an article in the POPULAR SCIENCE MONTHLY for May entitled “The Small College and Its President”—hence these words. Probably it is rarely the case, when a number of alumni, each more than fifty years of age, foregather and begin to talk over old times, that some one doesn’t tell the story of the time he and others put a cow in the college chapel. These stories can not all be true—there haven’t been cows enough.
THE last few years have witnessed a friendly controversy between the champions of nature and the champions of nurture, over the forces that are responsible for greatness. The nature advocates have insisted upon the importance of heredity in shaping men’s lives.
THE reason for the existence of sex is one of those biological problems which has long perplexed the scientific world, and to-day its solution seems as remote as it did a century ago. Many remarkable discoveries have been made in regard to the microscopic structure and development of the germ cells.
THE ST. PAUL MEETING OF THE NATIONAL EDUCATIONAL ASSOCIATION
MAJOR LEON ABB BABWIN’S AB~ BBESS BEFOBE THE EUGENICS EBU CATION SOCIETY
Louis AGASSIZ established in 1873 a marine biological laboratory on the Is land of Penikese in Buzzard's Bay, south of Wood `s Hole. Following his death the school was abandoned, but the plan was renewed in 1880 by the establishment of a seaside laboratory at Annisquam, in which Alpheus Hyatt was especially active.