Page:Popular Science Monthly Volume 24.djvu/261

Rh processes of growth and of change are evident enough to be familiar, but it is the reason for these phenomena which so often makes them miracles of wonder to the observer. Care, intelligence and skill will everywhere be seen, but there is a marked distinction between the growth that goes on under the supervision of an intelligence wholly-external to the form which is brought into being, as in the case of a crystal, and that development which is made according to instinctive or conscious tendencies implanted in the germ.

Tree, shrub and grass show evidence of effort on the part of the individual directed to quite obvious ends. The form assumed is in every instance such as to enable the plant to resist the violence to which it may be exposed. All the energies controlled by vital force are directed to supplying wants felt or anticipated. The tree in its growth develops strength where strength is needed, just as man by exercise increases his muscular power. In the formation of crystals another law predominates. It matters not whether these are safely hidden away in the caverns of the earth, or are exposed to risk of destruction upon its surface. They usually occur attached to one another, or to the faces of the rock. In the latter case, such as have unequal axes will be found so placed as to have their longest axes at right angles to the surface to which they are attached, or, if the surface be curved, this axis will be at right angles to the plane tangent to the curve at that point. This arrangement will be seen most plainly upon examination of a geode lined with quartz-crystals. It provides for the setting of the largest number of crystals upon a given surface, but puts them in the position of the least stable equilibrium quite unlike the sturdy posture assumed by a tree deeply rooted to the soil, and having its fibers most strongly interlaced in the region of its base. This setting of crystals displays them to the best advantage, but it leaves them more exposed to abrasion than would any other position, and more likely to be removed from their place. No provision has been made to guard against external violence, and in this may be found a striking point of distinction between an animate and an inanimate entity.



CHIAPARELLI continued his observations of the topography of the planet Mars during its last opposition, i. e., from October 26, 1881, to the end of February, 1882, and his results were communicated in a preliminary report early in March to the Accademia dei Lincei, of Rome.

Owing to the prevailing weather, his observations were restricted 