The body of the cataleptic patient descends to the condition of less complex animal life, in which there appears a much greater simplicity of organization; and we well know, as we descend in the scale of creation, towards the cold-blooded single-hearted animals, and especially if we reach the _zoophyte_, in how exact a proportion to this simplicity of structure is the tenacity of life increased. “Fish,” says Sir John Franklin, “were taken out of the nets frozen, and became a solid mass of ice, being by a blow of a hatchet easily split open; they, however, recovered their vitality on being thawed.” A course of _systematic_ abstinence will enable us, if we wished it, to endure extreme privations, which a high feeder would soon sink under; and this is probably the discipline adopted by the fakirs of India, who fast so long under the influence of superstitious devotion. Vaillant’s spider lived without food nearly one year; John Hunter’s toad fourteen months; land tortoises eighteen months; a beetle three years; and two serpents, according to Shaw, five years; an antelope has survived twenty days without food; some dogs forty days; an eagle 23 days. Now all animals fall asleep at certain temperatures, which they cannot resist, but the common effect of _extreme_ cold is death. Dr. Solander was yielding to the influence of intense cold in _Terra del Fuego_, but was saved by the firmness of Sir Joseph Banks. Richmond, the black, lay down on the snow to sleep, and died. There is a close analogy between this state and the _hybernation_ of animals, although the causes are not similar. _Animalculæ_ often become torpid for lack of moisture, and, even after the lapse of twenty-seven years, have been revivified by water. The small _furcularia anastobea_ will repeatedly become animated and lively by a single drop of water, its previous condition being completely quiescent. The snail, the alligator, indeed most of the _ophidian_ and _saurian_ reptiles, assume the torpid state in a period of extreme drought; and Humboldt states this also of the _centenes solosus_, a Madagascar hedgehog. This hybernation of animals, as of the marmot and the dormouse, resembles the deep sleep arising from cold of a _certain_ degree; for if this be _intense_, they will sometimes be momentarily roused from it. They may be constantly kept awake by heat and powerful light. Thus hybernation and the _sleep of plants_ take place from the withdrawal of _stimuli_; _heat_ being the _animal_—_light_ the _vegetable_ stimulus. CAST. The sleep of plants? a fiction surely!