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Sarracenia drummondii. Side-saddle Flower. Carolina.
Sarracenia purpurea.

N. America.
ORD. ROSACEE.
Cephalotus follicularis. New Holland

Pitcher Plant. New Holland.

The following communication was then read :ON A FRESH-WATER SPONGE FROM BAHIA.

Spongilla Coralloides. Bowerbank.

By T. HIGGIN, F.L.S. This interesting species was first made known by Mr. William Bragge, of Sheffield, now an alderman of that town, and an active supporter of the Sheffield Public Museum, who presented an example of it, from the River Winguay, one of the tributaries of the Amazon, to the Museum of the Royal College of Surgeons, London. This specimen was afterwards named and described by the late Dr. Bowerbank in his Monograph of the Spongillidæ, published in the Proceedings of the Zoological Society, in 1863. Another example, also from the same locality, exists in the Sheffield Public Museum, likewise the gift of Mr. Bragge ; and the British Museum possesses a fine specimen, presented by the late Mr. McAndrew, said to have come from the fresh water of the River Paraguay. The very fine specimen before us this evening has lately been received by the Liverpool Free Museum from Mr. George Higgin, C.E., at present residing at Buenos Ayres. It was obtained by him in March last, in the Rapids of the River Uruguay, above the town of Salto, the water at the time being lower than it had ever been known to be previously; it was then only running through the fissures of the rocks, but three months afterwards the river was forty feet deep at Salto.

This fresh-water sponge differs from all other known species of Spongilla, in appearance and in its mode of growth. All species from the South American rivers have been found to be much firmer than those from other parts of the world ; but this sponge is exceedingly rigid when fresh as well as when dried, and the sarcode is very crystalline, having quite a siliceous appearance. It is quite smooth, and grows in the form of erect, long, slender, digitiform processes, rising from a more or less thin spreading base, having much of the appearance of a Halichondroid marine sponge, found in the River Mersey, which Dr. Bowerbank identified as his Isodictya varians, but is considered by Mr. H. J. Carter, to be a variety of Chalina oculata, a sponge probably of world-wide distribution. This River Mersey sponge grows in brackish water, and seems, indeed, to have a liking for fresh water, since it was found in greatest quantity in a water-course formed by a stream of fresh water issuing from the stationary engine at the old Egremont Ferry House. The Spongillæ generally are of a soft texture, with a prickly appearance, and are usually found coating sticks and stones in shallow places, or embracing the small submerged branches of trees growing on the margins of rivers. Spongilla Coralloides, on the contrary, is found in the deepest parts of the river, which are probably never quite dry.

All species of Spongilla, with the exception of coralloides, are found in localities where they are subject to exposure to the air and heat during seasons of drought, or when the receding waters of rivers leave them high and dry. They must then of course perish, but the ova are protected with a thick crust, formed of siliceous spicules, of peculiar shapes specially adapted to the purpose, set in a cork-like substance. In this capsule the germ of the future sponge remains safe under the fiercest heat and most trying circumstances, until, with the return of copious rains, its native element again

surrounds it. Then its cork-like buoyancy raises it to the surface of the water, its contents issue through a small round aperture left in the capsule (hermetically sealed during the drought), and, caught by the first branch, twig, or floating stick, the development of the embryo sponge very rapidly proceeds. Spongilla coralloides, living in the deepest parts of these mighty South American rivers, is never exposed to the heat of the sun or to drying winds, and therefore its ova need no such protection as those of the other species, and we are not surprised to learn that the most diligent search has hitherto failed to discover in it any of the capsules peculiar to the Spongillidæ. Nothing is indeed known as to the reproduction of this species, and it will be very difficult to acquaint ourselves with it, because it is in the oviparous state when the waters of these rivers reach their greatest depth.

Differing as it does in its outward form from other freshwater sponges, and bearing a strong resemblance to some littoral species, the question naturally arises, Has this sponge always been a fresh-water species ? It certainly is a genuine fresh-water sponge now, and exists hundreds of miles above any point reached by tides, but it may not have been always so, and perhaps the further investigation of the sponges found on the coast may throw some light upon this interesting enquiry. It is possible that this remarkable sponge may by-and-by be found to be descended from a marine species, which has survived the changes which have been slowly taking place over a long period of time, and gradually adapted itself to the altered condition of its surroundings.

The waters of the Uruguay, at Salto, have very strong petrifying qualities, and Mr. George Higgin has kindly supplied us with the following analysis of the water from which this sponge was taken. It is remarkable for the large quantity of Silicic Acid it contains, and the absence of Chlorine:

Analysis by Professor Kyle, of Buenos Ayres, of water taken

from the River Uruguay (middle of the stream), in
front of Salto, November, 1877 (river full).

Parts per million.
Silicic Acid -

18:50
Carbonic Acid -

7.30 Sulphuric Acid

1:30 Lime

5.50 Magnesia

1.90 Potash

1.50

1.00
Oxide Iron
Chlorine

traces.
Nitric Acid

Soda

37.00

Mr. C. H. STEARN exhibited a new portable and rapid Sprengel pump and MʻLeod's gauge for low pressures. The object of the apparatus was to obtain a nearer approach to a vacuum, for the action of a column of mercury, than was at present attainable.

Mr. T. J. MOORE exhibited the following selection from additions to the Free Public Museum since the last Session :

Specimens from an extensive collection of fossil shells, chiefly from the Paris basin, presented by Mr. Frank Archer and his brother, Staff Surgeon-Major S. Archer.

A remarkably fine dried specimen of Physalia, or “Portuguese Man-of-war," retaining much of the brilliant life tints, prepared by Captain Mortimer, Associate of the Society; together with photographs greatly enlarged under the microscope by Dr. J. Habirshaw, of New York, of the thread-cells, &c., of Physalia, previously prepared by Captain Mortimer.

A selection of mounted skeletons illustrating types of all the classes of Vertebrates, prepared and presented by Mr. Alfred Higginson.

A series of Corals and Sponges from Honduras, collected and presented by Staff Surgeon-Major S. Archer, Corresponding Member of the Society.

Teeth of the Diprotodon Australis and Macropus Titan, extinct gigantic Marsupials of Australia, presented by Dr. George Bennett, of Sydney.

A Striped Bonito fish, taken off the Isle of Man, and rare in the British seas, presented by Messrs. Duncan, of St. John's Market, Liverpool.

Selections from the Rutter-Phillips' Collection of Minerals, recently presented to the Free Museum by the Trustees of the Liverpool Medical Institution. This important collection was made by the late Mr. William Phillips, and formed the basis of his well-known text books on Mineralogy.

The type specimen of Gladius Martinii, Marrat, a new shell from Cebu, Philippine Islands, from the collection of Mr. S. Trice Martin, of Manchester, recently figured and described by Mr. Marrat in the Leeds Quarterly Journal of Conchology, and presented by him to the Free Museum.

SECOND ORDINARY MEETING.

ROYAL INSTITUTION, October 29th, 1877. JOHN J. DRYSDALE, M.D., PRESIDENT, in the Chair.

Messrs. J. C. Rosenheim, R. F. Green, and E. Whalley were elected Ordinary Members.

The HONORARY SECRETARY reported some proceedings

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