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Page:Popular Science Monthly Volume 34.djvu/512

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the best tests of specific value next to genetic incapacity. The assumption finds its greatest support in genesis among the higher animals, and the most thoroughly differentiated species; but the whole subject becomes complicated as we descend in the organic scale, and hybrids between what naturalists generally separate as good species are far more frequently fertile among plants and lower animals than was formerly supposed; while physiological selection, as we have just seen, may render genesis impossible, or at least prevent it, between varieties and incipient species. In this light, hybridity becomes an important factor in the modification of species. Unnecessary importance has been given, in my judgment, to the fact that domestic and wild species differ in the fertility of their crosses. It is assumed, for instance, that all the known breeds of domestic dogs would be fertile inter se and produce fertile crosses. It seems to me, on the very face, a preposterous proposition, and that many of the breeds of domestic dogs are as distinct specifically, and even generically, so far as this test is concerned, as they are in structure and other characteristics. Who, for instance, has ever known or heard of a cross between a bull-dog and a lap-dog, or between a Newfoundland and a black-and-tan? The difference in size alone would seem to render such a cross, if not a physiological or a physical, at least a practical, impossibility; so that hybridity among domestic animals tends to essentially the same result as among wild animals, and confirms its importance as a differentiating factor.

[To be concluded.]



IN this age of wholesale educational machinery the faithful record of any school, individual in its character, ought to be of interest to all who seek better results in practical ability than our present systems of instruction succeed in giving. But, when the school departs widely from recognized standards, its record is of double value, as calling in question' prevalent customs, and affording a new criterion for the judgment of current methods. The tendency of instruction is to become set in its ways. Teachers follow precedent and reach formalism.

But from time to time particular individuals are found who ask the reason of this or that practice, and call in question its value as a means of culture. Hence arose the "teachers' institutes" in this country. They were first organized in the State of New York, in 1846. They grew naturally out of the progress in