Page:Popular Science Monthly Volume 4.djvu/40

30 troughs of water so arranged as to imitate as closely as possible the natural conditions necessary for the development and growth of the fish. Properly managed, ninety per cent, of the eggs will hatch out: the young fish are turned into the river when they are about a year old; if they can be kept two years in tanks large enough, with plenty of running water, so much the better for the prospect of their reaching the sea in safety.



When we can make up our minds to keep all our pollutions out of our rivers, and build "salmon-ladders" over all the wears, so as to give the fish a fair field, and enable them to run up-stream unimpeded, then, and then only, shall we see salmon as plentiful throughout the country as it is said to have been in the North a century ago, when apprentices are reputed to have stipulated in their indentures that they should be fed on salmon not more than three days a week. Without this, all our efforts to stock our barren rivers with artificially-bred fry will prove comparatively unavailing.—Nature.



NE further instance of the need for psychological inquiries as guides to sociological conclusions may be named—an instance of quite a different kind, but one no less relevant to questions of the time. I refer to the comparative psychology of the sexes. Women, as well as men, are units in a society, and tend by their natures to give that society certain traits of structure and action. Hence the question, Are the mental natures of men and women the same? is an important one to the sociologist. If they are, an increase of feminine influence is not likely to affect the social type in a marked manner. If they are