The causes of the elongation of vegetables are, {273} however, not very plain. We have noticed, that the deeper the seed is placed in the ground, the braird rises the higher above ground, even when the seeds at the different depths have been equally moist. This might admit of explanation, but having already occupied too much space with this subject, we shall only remark further, that in close woods, the trees elongate, because they are precluded from extending laterally. The top buds, from receiving more of the stimulating or nourishing influence of the dew, sun’s rays, fresh unvitiated air, invigorating motion of the winds, and perhaps of electricity[54], {274} throw out a greater continuation of shoot than the under branches; nearly the whole nourishment from the soil being on this account drawn up and consumed by these top shoots, and the lower overshadowed twigs and branches languishing and dying from the absence of these advantages. Besides this extension of top shoots, by the greater continuation of leaves, or links of life, occasioned by the above causes, these shoots, owing to the moist atmosphere of the wood, also push out into longer spaces between the leaves. However, these top branches do not push sun-ward, but merely in opposition to gravity. Sir Henry states, that “trees certainly possess some heat, otherwise they would be killed during severe frosts.” Our belief of the vital heat of vegetables is placed on a much better foundation than {275} this _otherwise_; otherwise our credence would be far from philosophic. Freezing cold affects many vegetables as well as some of the lower animals, only by mechanical injury, in rending the vessels by means of the expansion of the contained fluid. Now, if these vessels are not quite full of fluid, if the fluid be of such a nature as not to congeal into greater size, or if the body be small, and the vessels elastic, to yield to expansion without fracture—the vegetable or animal will often resume vitality, on being thawed from thorough congelation. We have rendered potatoes, turnips, and fruits, frost-proof, at least unless the frost was intense, by a slight desiccation caused by exposing them a short time to the air after being taken from the ground or tree[55]. In the cases where fishes and reptiles have been found {276} frozen so hard as to require a hatchet to dissect them, and reviving on thawing, it will be found that the fluids were principally oleaginous, which do not expand in congealing; and in the case of insects being frozen in masses during the night, and resuming their liveliness next day in the sun, we think, if their fluids have congealed at all, that either the vessels must have yielded, being elastic (which might more likely take place in a small body, without general fracture and derangement), or that the fluids had not extended by being congealed; but it is very probable, though frozen together in a mass of water and mud, that their