Page:Popular Science Monthly Volume 27.djvu/209

Rh be in the abstract, is impracticable under existing social conditions, which are in many cases such that men get what they have neither earned nor otherwise equitably received, and in many cases such that they are prevented from earning anything; then my reply is, by all means, where this condition of things is due to unjust arrangements, let us rectify these arrangements as fast as we can. But let us not adopt the disastrous policy of establishing new injustices for the purpose of mitigating the mischiefs produced by old injustices.—Contemporary Review.



EW natural groups present so many remarkable illustrations of several of the most important general laws which appear to have determined the structure of animal bodies as that of the whales. We find the effects of the two opposing forces—that of heredity or conformation to ancestral characters, and that of adaptation to changed environment, whether brought about by the method of natural selection or otherwise—distinctly written in almost every part of their structure. Scarcely anywhere in the animal kingdom do we see so many cases of the persistence of rudimentary and apparently useless organs, those marvelous and suggestive phenomena which at one time seemed hopeless enigmas, causing despair to those who tried to unravel their meaning, but now eagerly welcomed as beacons of true light, casting illuminating beams upon the dark paths through which the organism has traveled on its way to reach the goal of its present condition of existence.

It is chiefly to these rudimentary organs of the Cetacea and to what we may learn from them that I propose to call your attention. In each case the question may well be asked, Are they survivals, remnants of a past condition, become useless owing to change of circumstances and environment; or are they incipient structures, beginnings of what may in future become functional and important parts of the economy?

The term "whale" is commonly but vaguely applied to all the larger and middle-sized Cetacea, and, though such smaller species as the dolphins and porpoises are not usually spoken of as whales, they may to all intents and purposes of zoölogical science be included in the term. Taken all together the Cetacea constitute a distinct and natural order of mammals, characterized by their aquatic mode of life and external fish-like form. The body is fusiform, passing anteriorly into the head without any distinct constriction or neck, and posteriorly tapering off 