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THE POPULAR SCIENCE MONTHLY. 



next cause of monstrosities mentioned was 

 such as operated directly on the fatus 

 in uiero. The generative matter may be 

 perfect and fully representative, but certain 

 morbid influences may act directly on the 

 foetus. Dr. Armor instanced the experi- 

 ments made in producing malformations by 

 submitting hens' eggs to various mechani- 

 cal influences during incubation. In con- 

 clusion, he held that all causes of malforma- 

 tion would come under one of two heads : 

 Tbey are either generative or mechanical 

 sometimes one operating, sometimes the 

 other, sometimes both. 



Habitat of the Croeodile. Till recently 

 the two American species of crocodile, de- 

 scribed by Cuvier, have been supposed to 

 be confined to South America and the West 

 Indies. In 1870 Prof. Wyman identified a 

 skull from Florida as belonging to Cuvier's 

 species, Crocodilus acutus. Mr. William T. 

 Hornaday now describes in the American 

 Naturalist two specimens male and female 

 of the Crocodilus acutus which he cap- 

 tured last year in the vicinity of Biscayne 

 Bay, on the southeast coast of Florida. 

 The male was fourteen feet in length, and 

 his girth at a point midway between fore 

 and hind legs was five feet two inches. His 

 teeth were large and blunt ; his head rugose 

 and knotty, with armor-plates very large 

 and rough. On dissection it was found 

 that during life he had sustained serious 

 bodily injuries, probably in battle. Three 

 of his teeth were shattered ; the tibia and 

 fibula of the right hind-leg had been broken 

 in the middle and again united, also one of 

 the metatarsal bones of the same limb ; 

 the tail had been docked, and two of the 

 vertebrae had grown together solidly. 



The female measured ten feet eight inch- 

 es. Her head was regular in outline, 

 comparatively smooth, with white, regular, 

 and sharp plates, even in surface and con- 

 tour, and colors very marked. The entire 

 under-surface of both specimens was pale- 

 yellow, shading gradually darker up the 

 sides with fine irregular streaks and spots 

 o*f black. The general appearance of the 

 female was decidedly yellowish, while the 

 back and tail of the male showed an almost 

 entire absence of yellow, the prevailing 

 color being a leaden, lustreless black. 



While in Florida the author saw the skulls 

 or other remains of three other crocodiles. 

 He observes that all the specimens were 

 taken in water that is brackish about half 

 the time. 



Effects of Strain on the Magnetism of 

 Soft 5ron. The following account of exper- 

 iments made by Sir William Thomson, with 

 a view to ascertain the effects of stress up- 

 on the magnetism of soft iron, we take from 

 the Telegraphic Journal. Wires of steel 

 and of soft iron, about twenty feet long, 

 were suspended from the roof of the physi- 

 cal laboratory of Glasgow University. An 

 electro-magnetic helix was placed around a 

 few inches of each of the wires, so that the 

 latter could be magnetized when an electric 

 current was passed through the former, the 

 induced current thus produced in a second 

 helix outside the first being indicated by a 

 second galvanometer. With steel wire, the 

 magnetism diminished when weights were 

 attached to the wire, and increased when 

 they were taken off; but with " special " 

 soft-iron wire (wire almost as soft as lead), 

 the magnetism was increased when weights 

 were put on, and diminished when they 

 were taken off. Afterward he discarded 

 the electrical apparatus ; and, by suspend- 

 ing a piece of soft wire near the magnet- 

 ometer, consisting of a needle a small frac- 

 tion of a grain in weight, with a reflecting 

 mirror attached, the wire was magnetized 

 inductively, simply by the magnetism of the 

 earth, and changes in its magnetism were 

 made by applying weights and strains, the 

 changes being then indicated by the mag- 

 netometer. 



The Origin of Astronomy. Like that 

 of many other sciences and arts, the origin 

 of astronomy has been ascribed to various 

 nations of antiquity, and it is very doubtful 

 if any one of these can lay exclusive claim 

 to the credit of having been its founder. 

 The succession of day and night and of the 

 seasons, the phases of the moon, and the 

 motions of the heavenly bodies, must have 

 enlisted the attention of man from the ear- 

 liest times and in every clime. The result 

 would naturally be a more or less perfect 

 system of astronomy. Some nations, no 

 doubt, from one cause or another, culti- 



