Vitality can be so divided in the earthworm, that, as demonstrated by the experiments of Spalanzani, each of the severed parts carries life enough away to set it up as an independent animal; while the polypus, a creature of still more imperfect organization, and with the vivacious principle more equally diffused over it, may be multiplied by its pieces nearly as readily as a gooseberry bush by its slips. It was sufficiently curious, however, to see, in the case of this brown lizard, the least vital half of the creature so much more vivacious, apparently, than the half which contained the heart and brain. It is not improbable, however, that the presence of these organs had only the effect of rendering the upper portion which contained them more capable of being thrown into a state of insensibility. A blow dealt one of the vertebrata on the head at once renders it insensible. It is after this mode the fisherman kills the salmon captured in his wear, and a single blow, when well directed, is always sufficient; but no single blow has the same effect on the earthworm; and here it was vitality in the inferior portion of the reptile,--the earthworm portion of it, if I may so speak,--that refused to participate in the state of syncope into which the vitality of the superior portion had been thrown. The nice and delicate vitality of the brain seems to impart to the whole system in connection with it an aptitude for dying suddenly,--a susceptibility of instant death, which would be wanting without it. The heart of the rabbit continues to beat regularly long after the brain has been removed by careful excision, if respiration be artificially kept up; but if, instead of amputating the head, the brain be crushed in its place by a sudden blow of a hammer, the heart ceases its motion at once. And such seemed to be the principle illustrated here. But why the agonized dancing on the sward of the inferior part of the reptile?--why its after painful writhing and wriggling? The young eel scooped from the stream, whose motions it resembled, is impressed by terror, and can feel pain; was _it_ also impressed by terror, or susceptible of suffering? We see in the case of both exactly the same signs,--the dancing, the writhing, the wriggling; but are we to interpret them after the same manner? In the small red-headed earthworm divided by Spalanzani, that in three months got upper extremities to its lower part, and lower extremities, in as many weeks, to its upper part, the dividing blow must have dealt duplicate feelings,--pain and terror to the portion below, and pain and terror to the portion above,--so far, at least, as a creature so low in the scale was susceptible of these feelings; but are we to hold that the leaping, wriggling tail of the reptile possessed in any degree a similar susceptibility? _I_ can propound the riddle, but who shall resolve it? It may be added, that this brown lizard was the only recent saurian I