SURFACE CHARACTERS OF THE PLANET MARS. 249 



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 an- 

 other, 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 sur- 

 face 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 un- 

 like 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 inani- 

 mate entity. 



SURFACE CHARACTERS OF THE PLANET MARS.* 



SCIIIAPARELLI 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 

 * Translated for " The Popular Science Monthly " by Marcus Benjamin, Ph. B., F. C. S. 



