382 



THE POPULAR SCIENCE MONTHLY. 



in France, but hitherto without success. 

 The latest remedy, one from which great 

 results were expected, is sulphuret of car- 

 bon. It was held that this substance is 

 fatal to the phylloxera, but perfectly harmless 

 to the vines. As to the first point, there ap- 

 pears to be no reason to question the benefi- 

 cial effects of the sulphuret, but not so with 

 regard to the second, if we may put any 

 faith in the experiments of Lecoq de Bois- 

 baudrant. According to him, sulphuret of 

 carbon kills the vine as well as its parasite. 



Migrations of Insects. — The following 

 historical facts will give an idea of the 

 enormous magnitude sometimes attained by 

 migrating swarms of insects. After the 

 defeat of Poltava, while retreating through 

 Bessarabia, Charles XII.'s army was march- 

 ing through a defile, when suddenly the 

 men and horses were brought to a halt, being 

 blinded by a living hail precipitated from a 

 thick cloud which intercepted the light of 

 the sun. The coming of the locusts was 

 heralded by a whizzing sound like that 

 which precedes a storm of wind, and the 

 noise of their wings and of their bodies as 

 they clashed together was greater than the 

 roar of breakers on the sea-shore ! Gener- 

 al Levaillant saw, at Philippeville, Algeria, 

 a cloud of locusts twenty to twenty-five 

 miles in length, which, when it descended 

 to the earth, formed a layer over an inch in 

 thickness. 



Toward the close of 1864 the cotton 

 plantations of Senegal were destroyed, and 

 a living cloud was seen to pass over the 

 country from morning till night : the rate 

 at which it moved showed that it was 

 about fifty miles long ; and this was only 

 the vanguard, for when the sun went down 

 a still denser cloud was moving on. The 

 English traveller, Barrow, states that in 

 Southern Africa, in the year 1797, these in- 

 sects covered the ground to the extent of 

 two square miles, and that having been 

 driven by the wind toward the sea, they 

 formed a drift near the coast nearly four 

 feet in depth and fifty miles long ! After 

 the wind changed, the stench of their putre- 

 fying carcasses was recognized at the dis- 

 tance of a hundred and fifty miles. 



The famines produced by the voracity 

 of these acridians are not the only evils 



they cause to men and animals; a pesti- 

 lential epidemic is oftentimes the result of 

 the foul emanations from their rotting bod- 

 ies. The invasions of these insects are 

 veritable national calamities. In 1835 China 

 was ravaged by them, and the sun and 

 moon were obscured. Wherever they alight- 

 ed the finest and richest crops were instantly 

 devoured and the fields left bare ; even the 

 contents of the barns were to a great extent 

 consumed by them. The people fled in 

 alarm to the mountains. In the submerged 

 districts, where there were no crops to de- 

 vour, the locusts penetrated into the houses 

 and destroyed the people's clothing. These 

 ravages, which began in April, continued 

 without interruption till the season of frost 

 and snow. 



Animal-like Functions of Plants. — In 



the Biological Section of the late meeting of 

 the British Association, Dr. Burdon Sander- 

 son read a paper on the electrical phenom- 

 ena which accompany the contractions of 

 the leaf of Venus's-Flytrap. It was re- 

 marked that in those structures in the 

 higher animals which are endowed with 

 the property of contracting when stimulated, 

 viz., nerve and muscle, this property is 

 associated with the existence of voltaic cur- 

 rents which have definite directions in the 

 tissue. It became suspected that such was 

 similarly true of the Sundew {Drosera\ and 

 Venus's-Flytrap (Dioncea mmcipula) and 

 some other plants. Mr. Darwin furnished 

 the plants necessary for experiment to Dr. 

 Sanderson in the laboratory of University 

 College, London. The result is, that the an- 

 ticipations of the existence of voltaic cur- 

 rents in these parts have been confirmed, 

 particularly in the leaf of Dioncea. The 

 doctor has established the fact that these 

 currents are subject, in all respects in which 

 they have been investigated, to the same 

 laws as those of muscle and nerve. This 

 may be regarded as one of the most inter- 

 esting of recent biological discoveries. 



Natural Varieties. — Nature's best efforts 

 in the vegetable kingdom sometimes seem to 

 be reached per sallum, and without any aid 

 from man. Recently in England a first-class 

 certificate was given by the Royal Horticul- 

 tural Society for a fine variety of gooseberry, 



