POPULAR MISCELLANY. 



125 



beria. He noticed that this line of dis- 

 tribution lies within the belt of the north 

 trade-winds, and conjectured the existence 

 of some connection between the two facts. 

 Probability was given to the conjecture by 

 the migratory habits of this spider in the 

 early stages of its growth. The young 

 spider emits from the spinnerets fine threads 

 in sufficient bulk to overcome the specific 

 gravity of the body, and it is borne through 

 the air like a balloon. We some time ago 

 gave an account of Mr. McCook's observa- 

 tions on ballooning spiders. Having found 

 this spider in localities lying in the track 

 of the northern trades, Mr. McCook made 

 an investigation to determine whether the 

 spgcies is distributed along the entire track, 

 and also whether it is to be found in 

 the track of the southern trades. The re- 

 sult is exhibited by the author in a map 

 which shows the existence of Saroies vena- 

 lorius in both belts of the trades, from the 

 east coast of America, across this continent, 

 the Pacific, and the whole Eastern Conti- 

 nent, to the west coast of Africa, thus gir- 

 dling the globe, with the exception of 54° of 

 longitude corresponding to the width of the 

 Atlantic Ocean. The inference is that the 

 distribution of this spider has been accom- 

 plished by means of the trade-winds. 



The Growth of Mushrooms. — It is gen- 

 erally supposed that mushrooms grow only 

 in the night, but those who have watched 

 them have observed that their growth is 

 nearly equal day and night. A correspond- 

 ent writes that not long since a flower-pot 

 was filled with dirt from the street, a plant 

 was placed therein and it grew rapidly. In 

 ten days a small mushroom made its appear- 

 ance, but in a few hours it toppled over and 

 perished. On the following day a larger 

 one of different species was discovered peep- 

 ing through the soil, and in the morning it 

 was just above the surface. Before nine 

 o'clock at night it attained its full height, 

 nearly four inches, although it was in the 

 sun several hours, and gradually expanded 

 its acorn-head into a hollow cone which 

 united with the hollow stem at the interior 

 of the apex. Its inner surface was lined 

 and evenly shirred with a black, velvety sub- 

 stance which made a fine contrast with the 

 milk-white, cobweb-like substance of the 



outer surface. During the day and night 

 the head was transformed into an umbrella- 

 like cap, which collapsed and died on the 

 fourth day. Others of different species, 

 made their appearance at dift'erent times, 

 showing that the streets of a city as well as 

 the soil of the country are filled with spores 

 of these seedless and flowerless plants ready 

 to show themselves whenever the conditions 

 of germination are favorable. They do not 

 propagate by seeds — they have none — they 

 propagate by spores, microscopically small, 

 which are driven hither and thither by winds 

 and lodged in various places, and when they 

 receive the requisite amount of moisture 

 and heat they germinate and grow to per- 

 fection, whether it be day or night. 



Mercurial Deposit oa Animal Teeth.— 



On the teeth of a sheep said to have been 

 poisoned by the herbage growing in the 

 neighborhood of a certain silver-mine in 

 Mexico, Mr. E. Goldsmith, of the Academy 

 of Natural Sciences of Philadelphia, noticed 

 a peculiar deposit of tartar, which was sup- 

 posed to consist of silver amalgam. Upon 

 examination this tartar was found to con- 

 stitute a thin scale covering the teeth to the 

 depth of about 0.2 millimetre. Viewed un- 

 der a lens of moderate power, the deposit 

 seemed to have been built up gradually from 

 within. Its lustre was truly metallic. Heat- 

 ed on platinum-foil it became black, show- 

 ing the presence of organic matter. Heated 

 in a tube closed on one end, at first a gray 

 cloud arose, then water and an oily matter 

 deposited themselves on the upper or cooler 

 end of the tube ; lower down near the now 

 carbonized test a metallic layer was recog- 

 nized with the aid of the lens. The pow- 

 dered substance being mixed with carbonate 

 of soda, and treated in the same way, the 

 result did not differ. If melted on coal with 

 the addition of carbonate of soda, there was 

 obtained a white enamel, but no metal what- 

 ever. In nitric acid the tartar was soluble 

 as long as the solution was concentrated; 

 if diluted with water, a turbidity, caused by 

 the separation of an organic matter, was 

 formed. This organic matter was soluble 

 in caustic ammonia, and from this ammoni- 

 acal solution it was again precipitable by 

 nitric acid ; the precipitate was flocculent, 

 it carbonized when heated, and left no resi- 



