HARDWICKE'S SCIENCE. GOSSIP. 



S9 



with those of the three authors. I give you 1 the 

 results:— Mudie, vol. i. p. 92, edition of 1834, says, 

 " The eye of the Kestrel is peculiarly brilliant ; the 

 irides are rich brown, which contrasts well with the 

 dark stripe and the pale feathers at the base of the 

 bill and over the eye." Macgillivray, "British 

 Birds," vol. hi. p. 327, edition of 1S40, distinctly 

 says, " irides hazel." Wood, " Illustrated Natural 

 History," vol. ii. p. 82, edition of 1S62, does not 

 mention the iris at all; but he says, "the legs, toes, 

 cere, and orbits of the eyes are yellow." It is never 

 safe to quote from memory.—/. Y. H. 



Otters. — Two fine otters have been taken during 

 the winter in this place, near the junction of the 

 rivers Thames and Wey. — Arthur R. Graham, Wey- 

 bridge. 



"Eye-stones" (p. 21). — There is a very interest- 

 ing notice on these objects in Humboldt's " Travels 

 to the Equinoctial Regions of America" (Bonn's 

 edition, i. 197), which I beg leave to copy :— "Of 

 all the productions on the coasts of Araya, that 

 which the people consider as the most extraordinary, 

 or we may say the most marvellous, is 'the stone 

 of the eyes' (piedra de los ojos). This calcareous 

 substance is a frequent subject of conversation, 

 being, according to the natural philosophy of the 

 natives, both a stone and an animal. It is found in 

 the sand, where it is motionless ; but if placed on a 

 polished surface, for instance on a pewter or earthen 

 plate, it moves when excited by lemon-juice. If 

 placed in the eye, the supposed animal turns on 

 itself, and expels every other foreign substance that 

 has been accidentally introduced. At the new salt- 

 works, and at the village of Maniquarez, these stones 

 of the eyes (they are found in the greatest abundance 

 near Cape Araya) were offered to us by hundreds, 

 and the natives were anxious to show us the experi- 

 ment of the lemon-juice. They even wished to put 

 sand in our eyes, in order that we might ourselves 

 try the efficacy of the remedy. It was easy to see 

 that the stones are thin and porous opercula, which 

 have formed part of small univalve shells. Their 

 diameter varies from one to four lines. One of their 

 two surfaces is plane, and the other convex. These 

 calcareous opercula effervesce with lemon-juice, and 

 put themselves in motion in proportion as the car- 

 bonic acid is disengaged. By the effect of a similar 

 reaction, loaves placed in an oven move sometimes 

 on a horizontal plane, — a phenomenon that has given 

 occasion, in Europe, to the popular prejudice of 

 enchanted ovens. The piedras de los ojos, introduced 

 in the eye, act like the small pearls, and different 

 round grains employed by the American savages to 

 increase the flowing of tears. These explanations 

 were little to the taste of the inhabitants of Araya. 

 Nature has the appearance of greatness to man in 

 proportion as she is veiled in mystery ; and the ig- 



norant are prone to put faith in everything that 

 borders on the marvellous." This information will 

 certainly satisfy your correspondent's wish to learn 

 more about eye-stones. I possess a great many 

 specimens in my collections, and would gladly ex- 

 change them for English diatomacese, mounted and 

 named. Messrs. Triibner & Co., GO, Paternoster 

 Row, London, will forward letters to my address. 

 — A. Ernst, Caracas, Venezuela. 



Freshwater Molluscs. — " Laid up for the 

 winter," — Anodonta cygnea, which inhahits a small 

 stream here, had buried itself deeply into the mud, 

 leaving only the extreme posterior margin of its 

 shell out, when I visited the rivulet on the 12th of 

 last October. Assiminea Grayana has a habit of 

 gathering together in great numbers around reeds, 

 &c, on the surface of the muddy Thames banks. 

 Conovulus denticulatus congregates in a similar 

 manner at the approach of cold weather, but under 

 stones, and such shelter as it can find on the river 

 banks. Clausilia laminata, which abounds on 

 chalky banks at Dartford, is fond of heaps of sticks 

 and decayed Clematis, from which, however, it comes 

 out in mild weather even in December and January, 

 when I have taken it crawling. Helix caperata is 

 active at intervals ; during the whiter a large pro- 

 portion of the shells die. Dead shells were most 

 numerous in a sample taken in January; and out of 

 about a hundred II. virgata, taken at the same.time 

 for examination, there was only one living shell. 

 The H. virgata had retired under the rubbish at the 

 bottom of an old chalk-pit; near the dead shells 

 were masses of eggs, apparently belonging to the 

 species. — Harry C. Leslie, Erith. 



The Mussel's Movement. — I remember having 

 seen it stated in a work on natural history that the 

 mussel has not the power of moving from place to 

 place, and that it remains permanently fixed to the 

 same spot. This, I believe, is the commonly re- 

 ceived opinion, but it is an erroneous oue ; for, 

 though the mussel does not often move, or to any 

 great distance at a time, yet it certainly has the 

 power of progression. To effect a movement, it 

 extends its tongue-like foot to its utmost length ; 

 then, securing itself by pressing the end of the foot 

 to the spot, it gradually draws itself forward, 

 breaking, at the same time, the byssus by which it 

 has formerly been attached. At every step it 

 secures itself temporarily by new byssus, which it 

 necessarily breaks at every move. — A. E. Murray. 



Sea-birds in Manchester. — On the 14th 

 February a sea-gull was shot in Peel Park, Salford. 

 During the severe weather which prevailed about 

 that time, several other sea-birds were noticed in 

 the same neighbourhood, and also large flocks of the 

 Fieldfare.- 67. H. II. 



