Page:Popular Science Monthly Volume 44.djvu/583

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
569
POPULAR MISCELLANY.

no reason for his belief, and showed himself not more but less reasonable than his companions. The crude theories and gross absurdities of phrenology are not in the least justified or excused by the present knowledge of cerebral localization; nor do the baseless speculations of Lamarck or Erasmus Darwin entitle them to be regarded as the forerunners of Erasmus Darwin's illustrious grandson. Up to 1859 impartial and competent men were bound to disbelieve in evolution; after that date, or at least so soon as the facts and arguments of Darwin and Wallace had been published, they were equally bound to believe in it. He discovers who proves, and by this test Harvey is the sole and absolute discoverer of the movements of the heart and of the blood."

 

Habits of Scorpions.—A study is contributed to Nature by Mr. R. J. Pocock, of the habits of living scorpions. They were made upon the two species Parabuthus capensis and Euscorpius carpathicus. The specimens were evidently nocturnal, spending the daytime huddled together in the corners of their box, or under pieces of wood, and wandering about at night. "It was easy, however, at any time during the day to rouse them from their sluggishness by applying a little artificial warmth to the box." If the warmth was very moderate, they would seek it and bask in it; but as it increased, even while the author could bear it for several minutes without inconvenience upon his hand, "they were at once in a state of consternation." While walking, both species carried their pincers well in advance of the head, where they served as feelers. Euscorpius dragged its tail along the ground; Parabuthus carried his, curled in a vertical plane, over the hinder part of the back. All scorpions appear to be carnivorous, and to live principally on insects or other articulated animals, but the species differ considerably in their choice of food from the variety offered them. "As soon as a cockroach is seized the use of the scorpion's tail is seen; for this organ is brought rapidly over the latter's back, and the point of the sting is thrust into the insect. The poison instilled into the wound thus made, although not causing immediate death, has a paralyzing effect upon the muscles, and quickly deprives the insect of struggling powers, and consequently of all chance of escape. If the insect, however, is a small one—one, in fact, that can be easily held in the pincers, and eaten without trouble while alive—a scorpion does not always waste poison upon it." The only one of the higher senses that seems to be highly developed is that of touch. M. L. Becker says that that sense and hearing are excessively developed, but Mr. Pocock finds no evidence of auditory organs, and the sight very poor. The external organs of touch are the hairs that thickly or sparingly cover various parts of the body; and the pectine or ventral combs appear to play an important part in this office. The stinging by a scorpion is not a random thrust, delivered indiscriminately at any part of a captured insect. The scorpion "generally feels carefully for a soft spot, and then with an air of great deliberation delicately inserts its sting into it. There can be little doubt that this care is taken that there may be no risk of damaging the point of the sting against a substance too hard for it. . . . The same care of the sting is shown in the carriage of the tail, this organ being curled in such a way that the point can not come in contact with any foreign bodies. Even when turned with a piece of stick, or irritated by being crawled upon by a cockroach, a scorpion is not often sufficiently provoked to use its sting. The tail is certainly used to knock aside the instrument or sweep off the insect, but the sides or lower surface of the organ are employed, the vesicle being carefully tucked down." The author did not find his scorpions so pugnacious as they are generally said to be, and he doubts if they ever deliberately commit suicide, though they may do so accidentally, or in desperation.

 

The Blue Mountains of Jamaica.—The first object that greets the eye of the voyager, as he nears the shores of Jamaica, says Commissioner Charles A. Ward, in his account of the island prepared for the Chicago Exposition, is the mass of dark blue mountain looming upon the horizon; and as he draws nearer and nearer, though peak and ridge assume clearer and more distinct shapes, each still retains the tint of deep azure that gives its name to the chain.