8 4 



SCIENTIFIC NEWS. 



July 27, I J 



and gnaw the lower leaves. In a few hours the pro- 

 mising harvesthasdisappeared, leaving merely the stubble 

 as a sad witness. 



When the army has thus marched for about 50 days, 

 devouring all before it, it stops. The insects rest, their 

 integuments split on the back, and they appear provided 

 with wings. 



They can still run and leap, but they can also rise in 

 the air. For about a week they fly up and down, and 

 then suddenly soar off in immense bands, flying at great 

 heights as long as the sun is above the horizon. At sun- 

 set they descend and pass the night on the ground, 

 resuming their flight the next morning. Soon they find 

 upon the eastern or southern slope of a mountain, or on 

 an arid plain, a spot suitable for depositing their eggs. 

 The females run and leap about excitedly, sounding the 

 ground here and there with their abdomen until a suitable 

 spot having been selected, they bore the earth eagerly. 



Nature has placed at their disposal admirable boring- 

 tools ; the extremity of their abdomen is armed with 

 instruments having the appearance of hooks, but which 

 we cannot describe here. The shaft is bored to the 

 depth of nearly two inches, when they cease excavating 

 and begin to lay. As the eggs are deposited they secrete 

 a frothy liquid, which envelops them. At the same time 

 each female covers her deposit with a layer of small 

 grains of sand agglutinated together with great regularity. 

 When thus covered, these egg-cases, buried to the depth 

 of an inch below the surface, are so completely confounded 

 with the soil that they escape even experienced eyes. 

 Only the Arabs are able to detect them. 



These egg-cases, or dotheca, shown in our illustration 

 borrowed from La Nature, in which the report of M. 

 d'Herculais is given in full, have the form of small 

 cylinders slightly bent, rounded at bottom, and flattened 

 at top. If we open one of these cases we find in it, 

 symmetrically arranged, from thirty to forty eggs of a 

 yellowish-white colour. 



According to an old belief prevailing in Algeria, the 

 locusts, miscalled crickets, which invade the country 

 from time to time, belong to the species Acridium pere- 

 grinum. They are supposed to be brought by the 

 Sirocco, from the Sahara and the Soudan. This is a 

 mistake ; they are bred in the arid and desolate moun- 

 tains of North Africa, and belong to the species Stau- 

 ronohis Maroccanus. 



This insect, which of course belongs to the orthop- 

 terous family of Locustida., or, as the French prefer to 

 call them, Acrididce, is, when mature, of medium stature 

 — the males being a little above an inch, and the females 

 i\ inches in length. It is of a reddish testaceous colour, 

 relieved with fawn-coloured spots. Its elytra are tes- 

 taceous, with scattered brown spots and marblings. The 

 wings are transparent. The design of the thorax ren- 

 ders it very easily recognisable. It has on each side a 

 slight, oblique, and arcuated keel of a light yellow, 

 bordered with brown within. On the sides is a round 

 brown spot from which there issues a light yellow spot 

 in the form of a crescent, more or less regular. 



Sensitiveness of Plants. — It is not well known that 

 plants, under certain circumstances, e.g., in their alterna- 

 tions of sleep and waking, if subjected to variations 

 of temperature, or if touched, perform certain move- 

 ments which lead us to admit their sensitiveness, and 

 compare certain of them with the lower members of the 

 animal world, possessing not, indeed, distinct nerves, but 



what we may call a diffused nervosity. According ioLa 

 Nature, M. Baillon has recently discovered a new fact in 

 support of this view. The tendrils are one of the chief 

 seats of the manifestations of that kind of sensibility 

 which is observed in plants. Those of Cissus discolor, 

 which the learned Professor of the Faculty of Medicine 

 has studied, are extremely interesting. If one of the 

 ramifications of a tendril are submitted to the slightest 

 friction, there is formed at once a node which becomes 

 the starting point of a curve. Mr. F. W. Oliver has also 

 observed in the labellum of ' Masdevallia muscosa, a speci- 

 men of which flowered at Kew last year, some very curious 

 movements. Some parts of the labellum possess such 

 an irritability that the touch of a hair, or the wing of an 

 insect, will make it assume quite abnormal positions. 



The Fauna of Water-Mains. — Under this name Dr. 

 Kraepelin (Cosmos) has studied the organisms found in 

 the water supply of Hamburg. The water is taken 

 direct from the Elbe without filtration. Hence many 

 animal species living in the river are introduced into the 

 underground conduits. Dr. Kraepelin has found about 

 fifty species. Among fishes the most numerous are 

 Gasterostens aculeatus, Gadus lota, Phuronectes flesits, and 

 especially the eel, some specimens of which reach the 

 length of a foot. It has even happened that narrow 

 pipes have been choked up by one of these fishes, just 

 as it occurred some time back in the east of London. 

 The Mollusca are represented by Gasteropods and 

 bivalves. Insects are very rare, but small crustaceans 

 swarm, and worms and polyzoa are numerous. The 

 latter line the interior of the pipes with a mossy growth 

 which interferes with the circulation of the water. A1-' 

 most all fresh-water fishes, as well as most Articulata 

 and their larvae are absent. Species which breathe air 

 from the atmosphere, and those which feed on plants 

 perish ; those which feed on detritus, and which breathe 

 the air dissolved in the water, survive. 



Locusts in Europe. — The same species which is lay- 

 ing waste certain districts of Algeria, is hard at work in 

 Hungary over a vast extent of territory, especially in 

 the counties of Moglod and Peczel, and in that of Pesth. 

 The fields of wheat, barley, and maize, as well as the 

 gardens, vineyards, and orchards, are being ravaged. 

 Heavy falls of rain do not seem to have destroyed the 

 insects. Another species is at work in Sardinia and in 

 the neighbourhood of Rome. 



A New Case of Parthenogenesis. — M. A. Ernst 

 (Cosmos) believes that he has found a case of partheno- 

 genesis in the vegetable world, in a plant which he has 

 discovered near Caraccas. This plant, which yields fruits 

 without having been fecundated, is named Disciphania 

 Ernstii. The discoverer has cultivated several specimens 

 of this plant with every precaution to prevent fecundation 

 by the conveyance of pollen, either 01 the wind or of insects. 



Hatching Ova by Electricity. — Searching through 

 some back numbers of the Oesterrichische Landwirth- 

 schaftlichc Wochenblatter, we found it stated, on the 

 authority of Dr. Virson, Superintendent of the Italian 

 Experimental Silk Farm at Padua, that the hatching of 

 silk-worm eggs may be accelerated by ten or twelve 

 days, and a yield of at least 40 per cent, larvae secured 

 by exposing the eggs for eight or ten minutes to a current 

 of negative electricity from a Holtz machine. 



