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THE POPULAR SCIENCE MONTHLY. 



are informed, " results from combined ac- 

 tion of configuration, character of soil, con- 

 stitution of underlying rock, and the form 

 of its surface. These four elements regu- 

 late natural drainage. Each must present 

 favorable conditions, or deadly waters will 

 accumulate on the surface or in hidden 

 strata. No plan of artificial drainage can 

 be completely successful unless based on a 

 thorough comprehension of the natural drain- 

 age system of the area under treatment. The 

 region above the Palisades on the Hudson 

 furnishes excellent illustration of these 

 statements. The plateau fronts the river 

 eastward with a bluff 300 feet high, and 

 westward slopes gently to the Hackensack 

 Valley. . . . All topographical conditions of 

 unusual health seem here present, and yet 

 malarial diseases abound. The reason of 

 this will probably be found in the configu- 

 ration of the rock. The dense basalt under- 

 lying the thin soil absorbs almost no water. 

 Its surface, originally nearly level, was worn 

 by glacial action into low, swelling ridges 

 and shallow rock-basins, many of which, 

 having no outlet, hold stagnant water as 

 great saucers would. If the rock were 

 either fissured or porous the height of the 

 plateau would insure perfect under-drain- 

 age." 



With the Palisades plateau the author 

 now contrasts the Ilelderberg plateau, also 

 situated near the Hudson River. Here, "an 

 escarpment 1,000 feet high bounds, on the 

 eastern side, the table-land, composed of hor- 

 izontal limestone resting on shales. From 

 the more level parts water does not pass off 

 by surface-streams. Low undulations di- 

 vide these areas into many separate basins, 

 each draining toward its own centre, where 

 a funnel-shaped opening in the limestone 

 receives the disappearing flow, whose future 

 course is subterranean. These basins are 

 from a few aires to 300 or 400 in extent. 

 When one covers about five square miles a 

 pond is formed at the point of central drain- 

 age, Ending outlet through fissures of the 

 limestone below. The plateau's elevation 

 insures that these waters sink at once many 

 hundred feet, or escape in springs along the 

 cliffs." Mr. Gardner then proceeds to show 

 how as at Sandusky, Ohio this same Ilel- 

 derberg limestone may, under different to- 

 pographical conditions, become one of the 

 most powerful producers of disease. 



A Formidable Araehnidan. Dr. B. F. 



Pope, U. S. A., contributes to Forest and 

 Stream some valuable " Notes on the Natu- 

 ral History of Southwestern Texas," from 

 which we take the following account of the 

 " vinagrone " (big vinegar, so called on ac- 

 count of the pungent secretion it ejects), an 

 araehnidan found in the vicinity of Fort 

 Stockton. In general appearance it resem- 

 bles a large scorpion, though belonging to 

 a different family. From the head to the 

 commencement of the tail the adult vina- 

 grone is full two inches long ; in breadth it 

 measures about three-quarters of an inch. 

 The thorax and head are amalgamated, 

 while the thorax and abdomen are separated 

 by flexible tissue. The legs are six in num- 

 ber, all attached to the thorax. The trunk 

 and head are protected by a single dorsal 

 plate ; the abdomen has sixteen distinct 

 dorsal and ventral laminae, which overlap ; 

 they would form continuous rings, were it 

 not that they are curiously separated later- 

 ally by elastic tissue. This division of the 

 abdominal rings affords considerable flexi- 

 bility, and gives the insect the appearance 

 of bearing about him an old-fashioned bel- 

 lows. From the terminal, dorsal, and ven- 

 tral plates is given off a series of rings, 

 which, after the third one, are fused into a 

 stiff spike or tail, that is usually three-fifths 

 of the length of the entire body, and cov- 

 ered with short bristles like the legs. This 

 is not a sting, nor does it seem to be the 

 duct through which the secretion is ejected. 

 It appears to be used principally as a pos- 

 terior feeler, and sometimes as an aid to 

 locomotion. 



From the head are given off two power- 

 ful brachials, each having four articulations. 

 They resemble the arms of a scorpion, and 

 terminate in sharply-curved pincers. The 

 threatening manner in which they are opened 

 and stretched out, when the insect is enraged 

 or is seeking for its prey, almost makes one 

 shudder. But the brachia are not its only 

 means of offense. Beneath the frontal plate 

 are two long, incurvated fangs. Connected 

 with these are two sacs, that, by pressure, ex- 

 ude drops of greenish liquid over the fangs, 

 and in them undoubtedly resides the true 

 venom of the insect. 



Of the bite of this animal the author 

 writes : " We have no good proof that the 

 bite of the vinagrone would be fatal to man, 



