SCIENTIFIC NEWS. 



[Jan. 27, I? 



feet on one side of the body only ; when these are 

 fatigued the feet on the other side carry on the worlc. 



The Intelligence and Development of the Oyster. — 

 The following facts on this subject appear from the 

 writings of Professors L. Morgan, Frank Buckland, and 

 Rev. W. Bingley. The oyster does not possess special 

 organs of sight, but the fringe of the mantle, its organ 

 of touch, is vaguely sensitive to light. It has no audi- 

 tory organs, but it appears to have some sense analogous 

 to smell or taste by which it can test the incoming 

 water. Mr. Bingley thinks that oysters are able to 

 derive some knowledge from experience. If removed 

 from spots constantly covered with water they open 

 their shells, lose their water, and die. But if laid down 

 in places from which the sea occasionally retires they 

 learn to keep their shells close until the tide returns. 

 They may be gradually trained to a longer and longer 

 exposure to the air without gaping — a fact which is 

 turned to practical account in the " oyster-schools " of 

 France. During the summer, when the oysters are out of 

 season, the development of the spawn, or " spat," as it 

 is technically called, takes place. The number of eggs 

 in an oyster in this condition ranges from 276,000 to 

 329,000. At last the mother-oyster opens her shell, and 

 the young issue forth like a puff of smoke. Each young 

 oyster at birth is provided with swimming organs in 

 the shape of delicate ciliae, and by their means begins to 

 play about the moment it leaves the maternal shell. This 

 swimming apparatus is lost as the oyster arrives at 

 maturity, and the creature thus loses the power of loco- 

 motion, and becomes comparatively a fixture. The 

 valves of the young oyster's shell are smooth and trans- 

 parent, symmetrical and united by a straight hinge. 

 The mouth is large and lies opposite the hinge, so there 

 are no gills. Between the valves there projects an oval 

 cushion supporting the swimming hairs by which the 

 young mollusk propels itself through the water. At 

 pleasure the cushion may be drawn back into the shell, 

 when the oyster sinks. It need scarcely be said that 

 only a small part of the cloud of young oysters escape the 

 attacks of their numerous enemies and survive to 

 maturity. 



Gibraltar. — We find in the Entotnologists' Magazine 

 a paper by Mr. James J. Walker, an officer of Her 

 Majesty's gunboat Grappler, on " A Year's Insect-Hunting 

 at Gibraltar." The insects that swarm about the rock are 

 of wonderful interest. There is scarcely a day through- 

 out the year on which butterflies may not be found, and 

 Mr. Walker enumerates fifty-five species for the limited 

 district, thirty of which have occurred on the rock itself 

 He has found 900 species of beetles, and is daily adding 

 to the number. Apart from the purely entomological 

 interest of the paper, the introductory portion is of great 

 value, being a lucid rc'siniic'in a few pages of the topo- 

 graphy of the rock and the immediate neighbourhood, 

 with sketches of the chief botanical, zoological, geological, 

 and meteorological features. As is well known, the 

 rock is the sole European locality in which the Barbary 

 ape is found in a wild state. These animals, reduced a 

 few years ago to less than a dozen individuals, have of 

 late greatly increased in numbers, and, being strictly pro- 

 tected, are very bold and fearless. The fig trees in the 

 gardens suffer so much from their depredations when the 

 fruit is ripening that it is found necessary to employ 



men to scare them away. The Barbary partridge, 

 though numerous on the rock as well as on the opposite 

 African coast, is, like the monkey, found nowhere else on 

 the European Continent. 



Edible Birds' Nests. — Large quantities of edible 

 birds'-nests are brought from the mammoth Gomanton 

 caves, which are situated about twelve miles to the 

 northward of Malapi, on the river Kinabatangan. The 

 nests collected are valued at 25,000 dollars per annum, 

 and the North Borneo Government in 1884 let the caves 

 at a yearly rental of 9,000 dollars. The height of one of 

 the vaults in these limestone caves is estimated at 900 

 feet, upwards of twice the height of St. Paul's, London ; 

 and some idea of the swarms of swallows (callocalia) 

 may be gathered from the statement that a steady column 

 of these birds has been timed by the watch to fly for 

 three-quarters of an hour from one of the apertures. All 

 these birds'-nests are sent to China, where they are 

 prized as a luxury in the well-known Chinese birds'-nest 

 soup. 



Introduction of Goats into New Guinea. — It is painful 

 to find that a number of misguided persons are turning 

 goats loose in New Guinea. As there are there no 

 carnivorous animals to keep these tree-destroyers in check; 

 the result may be the ruin of the magnificent flora of that 

 island, and ultimately of its fauna also. 



The Reproduction of Alcyonidium Gelatinosum. 

 • — Dr. Hincks, in his British Marine Polyzoa, pronounces 

 the individual polypides of this species unisexual. Mr. 

 W. A. Herdman, on the other hand, holds that 

 Alcyonidium gelatinosum is probably a hermaphrodite 

 in which the reproductive systems arrive at maturity at 

 different times in their life history. 



The Habits of the Hessian Fly. — Prof. Lindemanhas 

 communicated to the Bulletin de la Societe des A^aturalistes 

 de Moscou, two elaborate memoirs on the Hessian fly. 

 He concludes there is no universal remedy for this scourge, 

 because the manner of life of the insect and the condi- 

 tions of its propagation vary in different countries. Three 

 generations appear yearly near Moscow, one in spring, 

 one in summer, and one in autumn. Each of these must 

 find for its support green stems of grain capable of 

 remaining succulent during the twenty-eight days in 

 which the insect remains in the larval condition. Among 

 its insect enemies he notices a Geophilus (Creophilus), 

 the larva of a Cantharis, and a mite. 



The Kingfisher. — L. F. S., in a communication to 

 Land and Water, speaks of a tame kingfisher which he 

 found in a cottage on the banks of the Wye, near Here- 

 ford. On its owner pouring some water and a few 

 minnows into an earthen pan the bird came, and perching 

 on the rim of the pan soon captured all the fish, first 

 killing each one and then swallowing them whole. The 

 writer does not believe that the kingfisher catches his 

 booty in deep water. Another writer in the same paper, 

 S. B. Coates, found a kingfisher choking in an effort to 

 swallow a perch about 2i in. long. The fish was ex- 

 tracted, but the bird survived only for twenty-four hours. 



Weasels and Frogs. — That the weasel (Mustela 

 vulgaris) destroys frogs is proved by the following inci- 



