FOREIGN AND MISCELLANEOUS NOTICES 



law. Analogy would lead us to believe that 

 the extension of species over the earth original- 

 ly took place on the same plan on which it is 

 conducted at present, when a new island starts 

 up in the midst of the ocean, produced either 

 by a coral reef or a volcano. In these cases, 

 the whole surface is not at once overspread with 

 plants, but a gradual progress of vegetation is 

 traced from the accidental introduction of a 

 single seed, perhaps of each species, wafted by 

 winds, or floated by the currents. The re- 

 markable limitation of certain species to single 

 spots on the globe, seems to fiivor the supposi- 

 tion of specific centers. Professor E. Forbes 

 says, the hypothesis of the descent of all the 

 individuals "of a species, either from a first 

 pair, or from a single individual, and the conse- 

 quent theory of specific centers being assumed, 

 the isolation of assemblages of individuals from 

 their centers, and the existence of endemic or 

 very local plants, remain to be accounted for. 

 Natural transport, the agency of the sea, rivers, 

 and winds and carriage by animals, or through 

 the agency of man, are insufficient means in the 

 majority of cases. It is usual to say, that the 

 presence of many plants is determined by soil 

 or climate, as the case may be; but if such 

 plants be found in areas disconnected from their 

 centers by considerable intervals, some other 

 cause than the mere influence of soil or climate 

 must be sought to account for their presence. 

 This cause he proposes to seek in an ancient 

 connection of the outposts or isolated areas 

 with the original centers, and the subsequent 

 isolation of the former through geological 

 changes and events, especially those depend- 

 ent on the elevation and depression of land. 

 Selecting the Flora of the British Islands for a 

 first illustration of this view, Professor Forbes 

 calls attention to the fact, well known to bota- 

 nists, of certain species of flowering plants being 

 found indigenous in portions of that area, at a 

 great distance from the near assemblages of in- 

 dividuals of the same species in countries be- 

 yond it. Thus, manj' plants peculiar in the 

 British Flora to the west of Ireland, have the 

 nearest portion of their specific c?nters in the 

 north-west of Spain ; others, confined with us 

 to the south-west promontory of England, are, 

 beyond our shores, found in the Channel Isles 

 and the opposite coast of France; the vegeta- 

 tion of the south-east of England is that of the 

 opposite part of the continent ; and the alpine 

 vegetation of "Wales and Scotch Highlands is 

 intimately related to that of the Norwegian 

 Alps. The great mass of the Briti.-;h Flora 

 has its most intimate relations with that of 

 Germany. He believes, therefore, that these 

 isolated outposts were formerly connected to- 

 gether by chains of land, and that they liave 

 been separated by certain geological convul- 

 sions. Islands may be considered as the re- 

 mains of mountain chains, i)art of the Flora of 

 which they still exhibit, and the farther they 

 from continents, the more likely are the 

 to be peculiar. — Balfour's Man. Bot. 



SiNGUL.^R Electrical Phenomena. 

 Looms has submitted a paper to the American 

 Association for the advancement of Science, 

 on some remarkable electrical phenomena ex- 

 hibited in New- York. He states that for 

 months in success'on, electrical sparks, ac- 

 companied by loud snaps, have been observed 

 in several houses. 



" A stranger on entering one of these electri- 

 cal houses, in attempting to shake hands with 

 the inmates, receives a shock which is quite 

 noticeable and unpleasant. Ladies in attempt- 

 ing to kiss each other are saluted by a spark. 

 A spark is perceived whenever the hand is 

 brought near to the knob of a door — the gilded 

 frame of a mirror — the gas pipes — or any me- 

 tallic body — especially when this body com- 

 municates freely with the earth. In one house 

 which I have had an opportunity to examine, a 

 child in taking hold of the knob of a door re- 

 ceived so severe a shock that it ran otf in great 

 fright. The lady of the house in approaching 

 the speaking tube to give orders to the servants, 

 received a very unpleasant shock in the mouth, 

 and was very much annoyed by the electricity 

 until she learned first to touch the tube with 

 her finger. In passing from one parlor to the 

 other, if she chanced to step upon the brass 

 plate which served as a slide for the folding 

 doors, she received an unpleasant shock in the 

 foot. AVhen she touched her finger to the 

 chandelier (the room M-as lighted with gas by a 

 chandelier suspended from the ceiling) there 

 appeared a brilliant spark and a snap as in the 

 discharge of a Leyden Jar of good size. In 

 many houses the phenomena have been so re- 

 markable as to occasion general surprise and 

 almost alarm.'' 



After a careful examination, Professor L. 

 has come to the conclusion that the electricity 

 is excited by the fiiction of the shoes of the in- 

 mates upon the carpets of the houses. He ob- 

 serves: 



" By skipping once or twice across a room 

 with a shuffling motion of the feet, a person 

 becomes highly charged, and then upon bring- 

 ing the knuckle near to any metallic body, par- 

 ticularly if it have good communication with 

 the earth, a bright spark passes. In almost 

 any room which is furnished with a woolen cai'- 

 pct, and is kept tolerably warm, a spark may 

 thus be obtained in winter — but in some rooms, 

 the insulation is so good and the carpets are so 

 electrical, that it is impossible to waUt across 

 the floor, without exciting sutficient electricity 

 to give a spark." 



Fruitfulness promoted by late Pruning. 

 — By pruning at the rising of the sap, we in- 

 duce in trees, barren through over-luxuriance of 

 growth, a flow of that sap from the roots, which 

 produces vigor. What I call the fertilizing sap 

 is at that time not yet formed, since the leaves 

 which are its organs of formation, do not 

 exist ; the wood growth which is made 

 early spring, is owing then, entirely to the 



