Page:Popular Science Monthly Volume 22.djvu/759

Rh To the next objection, that the practice of vice is not inevitably suicidal, since many rascals live to attain as green an old age as the most righteous, it is sufficient to say that, plentiful as these exceptions may occasionally seem, their proportion to the whole number is at least as small as that of the exceptions to any other general law of biology. The policeman on the next corner will bear decided testimony that the number of scoundrels who survive their thirtieth year is astonishingly small, and he can point out any number of very troublesome members of the community who are ending their lives in penitentiary or poor-house hospitals, at an age when well-behaved men are just entering upon the serious business of life.

It is also demonstrable that the proportion of vicious men to the whole population is much less to-day than at any previous period in the history of the race. This shows conclusively the improvement of society by the self-destructiveness of vice. The proportion of bad men is steadily diminishing, because bad men die sooner, and propagate fewer, than good ones.



HERE is much uncertainty as to how the backboned or vertebrate animals began; but the best clew we have to the mystery is found in a little, half-transparent creature, about two inches long, which is still to be found living upon the English shores and the Southern Atlantic coast of the United States. This small, insignificant animal is called the "Lancelet," because it is shaped something like the head of a lance; and it is in many ways so imperfect that naturalists believe it to be a degraded form, like the acorn-barnacle—that is to say, that it has probably lost some of the parts which its ancestors once possessed. But, in any case, it is the most simple backboned animal we have, and shows us how the first feeble forms may have lived. Truly, it is only by courtesy that we can call him a backboned animal, for all he has is a cord of gristle, pointed at both ends, which stretches all along the middle of his body above his long, narrow stomach; while above this, again, is another cord containing his nerve-telegraph.

There are large fishes, too, which have this cartilaginous back-bone. The young shark has nothing but a rod of gristle or cartilage, and, though he is one of the strongest of sea-animals, he retains this gristly state of his skeleton throughout his life; however much he may strengthen it by hard matter, it never becomes true bone. 