Royal Physical Society.

Thursday, 28th February 1855.

ROBERT K. GREVILLE, LL.D., in the Chair.

The following Communications were read:

1. On Uigite, a new mineral (?) By M. FORSTER HEDDLE, M.D.

In a quarry near Uig, in Skye, I obtained indifferent specimens of Faroelite, a single crystal of Analcime, and a few pieces of a substance which, being unknown to me, I analyzed, and which may be considered new. Should this be admitted, I would propose for it the name Uigite. It occurs in small nests in the amygdaloid, which is here very vesicular, is not distinctly crystallized, being in radiated sheafy plates, somewhat resembling the structure of a plumose mica, but in general appearance intermediate between Faroelite and gryolite; colour white, slightly yellowish; lustre tremulous and pearly: hardness, 55, brittle; specific gravity, 2.284; before the blow-pipe fuses readily and quietly, with strong re-action of soda, to a white opaque enamel, which is not frothy. On analysis, it afforded 45 98 per cent. of silica, 21.93 of alumina, 16.15 of lime, 47 of soda, and 11-25 water. These proportions give equivalents,-silica, 7; alumina, 3; lime, 4; soda, 1; water, 9. The mineral, therefore, consists of 1 equivalent of a silicate of lime and soda (where the lime is to the soda as 4 to 1), 1 equivalent of a sesquisilicate of alumina, and 9 of water. The calculated percentage proportions of which compound are,silica, 4609; alumina, 21.93; lime, 1597; soda, 4.46; water, 11.55; which agree closely with the analytical results. No mineral has the above formula, which differs, however, from that of Faroelite (Mesole), merely in the insertion of the compound 2 (Ca O, Si O) + H O. 2. Remarks on the Scientific bearings of recent discoveries in Helminthology. By JAMES WARDROP, Esq.

3. Notice of a curious Metamorphosis in a Zoophyte-like Animal. By CHARLES W. PEACH, Esq., Wick.

In March last year, I obtained from a fisherman's line an old and much corroded valve of Psanombia ferroensis, which had been hooked up from deep water; on it I noticed jelly-like spots, and placed it in a shallow glass of sea water; the next day I fancied that I could make out, with my pocket lens, zoophyte-like animals. At once I transferred the shell in a watch glass, filled with sea water, to my microscope, and was delighted to find my suspicion correct, for after a little management, so as to catch the light, I could see the forms as figured (Fig. 1) attached to the shell by a short foot-stalk, a little inflated near the upper part, tipped with a slightly raised and rounded centre, from which extended four long and four short leaf-like arms, each granulated down the centre; one or two had, in addition, springing from these, delicate tentacle-like arms, probably in a farther stage of development. They were easily disturbed, but soon again displayed themselves; their transparency, added to this shyness, rendered it difficult to catch their forms. At first I thought they were the early stage of a Hydractina, and probably, H. brevicornis of Müller, mentioned in Johnston's second edition of The British Zoophytes," page 35. My next examination was on the 2d of April. After giving them a supply of sea water, they were still fixed; I could, however, perceive a dif

ference, the centre of the head more raised and cone-shaped, and the arms shorter. I continued my examinations daily; and on the 6th, instead of moored creatures, I had a fleet of probably one hundred minute, free, naked-eyed, medusoid-like beauties (Fig 2), jerking about in all directions, with the exception of size all alike, perfectly transparent; the umbrella

Fig. 2.

Fig. 1.

well rounded and pilose; the sub-umbrella large; each had four large ocelli-like bulbs on the edge of the mantle, furnished with a stiffly turnedup tentacle, tipped with a disk having a dark centre; this surrounded by a light ring, and outside a darker edge, dark but short bars arranged in a quincunx manner on these tentacula. The ocelli were composed of minute, dark granules. As well as these long tentacula, there were four smaller and shorter ones, also turned up, but no ocelli where the edge of the mantle is shown. On the lower part of the mantle runs a canal communicating with the bulbs of the large tentacula; in the canal I observed a granular circulation passing along, and, as if revolving in the bulbs and a short way down each large tentacle; into these bulbs smaller granules descended from the sub-umbrella, by the gastro-vascular canals; these canals extended to the upper part of the stomach, the stomach being attached to them, and is rounded on the upper part, and divided into four lobes; it then narrows and runs out bell-shaped to the quadrate mouth, which has four long lips fimbriated at the tips. They were very active up to the 10th, when some little change took place. I supplied small quantities of water, and used every precaution, from being anxious to see all I could of them. On the 11th they became sickly, and the upper part of the umbrella in eight festoons, the tentacula slightly drooping. On the 13th, nearly inactive, hyaline, and turned inside out. I began to hope that, as the mouth had become elongated into a peduncle-like form, they were about to become fixed again; they, however, dwindled away, and although I kept the water for months, I could trace nothing more. I have not yet seen Steenstrup's work on "The Alternation of Genera," therefore am unable to say whether it may be one of the interesting facts noticed by him. They differed in the fixed state from any of the zoophytes figured and described by Johnston; and when free from all the naked-eye medusæ figured in the monograph of Forbes, it may be one of the latter in its earlier stages, and probably is, from being pilose, this being the case with many of the young of the medusoid tribe which have fallen under my notice, and I have seen many. This is the most interesting of all. The most like the free state, is Lizzia octopunctata of Forbes, Pl. xii., fig. 3; it agrees thus far in the form of the umbrella, in

having 8 tentacular bulbs, 4 gastro-vascular canals, the shape of the stomach, quadrate mouth, and long fimbriate-tipped lips. It differs in being pilose, and having only 8 tentacula, instead of 20, viz., 3 at each large ocelli bulb, and 2 at each of the smaller ones; even this difference in the number of tentacula, &c., ought not to put it out of court, for I have seen, and have a long list of notes and numerous drawings of the strange changes from the young to the adult state of these lovely gems. At present I cannot spare the time to make the drawings and extend the notes. I present this fact, so that others may be aware that such transformations are to be met with on our own coasts, and that by watching for shells from deep water thus begemmed, a series of observatious may be made, and more facts collected, so that the true nature and phases of these Proteus-like objects may be made out.

4. A Letter was read from the Rev. H. M. WADDELL, Old Calabar, to ANDREW MURRAY, Esq., containing additional information regarding the new Electric Fish (Malapterurus Beninensis, Mur.) Mr Waddell writes as follows:-" As you attach some importance to an observation I had formerly made concerning the power of the small electric fish of this river to benumb other fish with which they come into contact, I should have verified my observation by renewed experiments. An opportunity soon offered of accomplishing this object, and I now communicate the result, which you will probably deem to be of a very satisfactory description. I have four electric fish in a large basin, the largest about six inches long, and as thick as the neck of a quart bottle; the smallest about three inches long, and the thickness of your finger. They have been there in a healthy state for some months. I procured eight small fishes, varying from two to three and a half inches in length, which I put in with the others. The electric fish continued, as usual, side by side, quiescent at the bottom, while their visitors swam and darted about in a lively manner, and even ventured down among their dangerous neighbours, rousing them to activity, passing through their ranks, and disturbing them not a little, without seeming to be either afraid of them or molested by them. They frequently rubbed sides without any effect similar to what I had before observed being produced, and I began to fear that my former observation would not be confirmed. Having watched their movements in vain, I retired for a while, but returned in half an hour to see how they were getting on. I then found the new-comers, all but one, the largest of them, lying at the bottom among the electric fish. Having taken out the seven which were evidently struck, I found four of the smallest quite dead and stiff, their backs twisted or curved, and their mouths gaping open. Three of them, though much benumbed, revived when transferred to another basin of water, and, after an hour or two, recovered perfectly, and were as lively as before. The one which escaped at first was left with his dangerous companions, but was not so lively as at the first. It would swim about a little, then sink, again rise and make a few darts, and then sink again. Tired of watching him, I went on with my book, but after a little returned, and found him quite dead, his back curved downwards very considerably, and his mouth gaping half an inch open. Taking him by the tail, I lifted him out as stiff as if frozen, and further, observed his colour quite gone; a very dark brown before, he was now as pale as ashes. I had noticed something of this change of colour in the first four affected, but not of so marked a kind as in this last one. The three which recovered from the first attack remained to be tried again, and were put in with the electric fish a second time, when quite strong and lively. They swam and frisked about as playfully and safely

as on the first occasion, and I watched them intently, and for a longer time than before, but observed no movement on the part of the electric fish, though the others sometimes darted down among them. They seemed to be more intent on eyeing me than minding their little visitors, one of which was nearly three inches long, the others about two each. Tired of looking and seeing nothing, I left them as before, and after a little returned, when all three were lying benumbed at the bottom. Being removed to another basin, one of them revived, the others were dead. The dead ones were not, however, so powerfully affected as their companions in misfortune; they were not rigid, nor contorted, nor pallid, nor gaping. Obviously they were not so severely struck as the others had been, the powers of the electric fish being probably by this time somewhat weakened. The one that still survived recovered completely to admit of a new experiment. I confess to some misgivings of feelings on subjecting it to a third and final trial; but a remark in your note, if the electric fish eat those they stunned, was yet unanswered. Therefore, in retiring for the night, I gave it to them for their supper, if they should have any fancy to make that use of their victim. But in the morning I found him, though dead, yet otherwise uninjured. If you ask me what do they live on? I cannot answer. Those with me eat nothing. They are on my study table, and I see them daily, but give them nothing. Even their water is seldom changed, yet are they strong and lively. As I am told that they lie much in the ooze at the bottom of the river, I have given them sand to lie on, which they sometimes stir up with their tails. A few times daily, but chiefly in the evening and early night, they plunge about and make the water muddy. I cannot learn that they have been ever found larger than a herring."

5. On the Reproduction of Cydippe pomiformis. By T. STRETHILL WRIGHT, M.D. (This paper appears in the present number of the Journal.)

6. On Two new Actinias from Arran. By T. STRETHILL WRIGHT, M.D. (One of them is described and figured in the present number of the Journal.)

Wednesday, 26th March. WILLIAM H. LOWE, M.D., President, in the Chair.

The following Communications were read :—

1. On Zoological Classification. By Professor M'DONALD.

2. Revision of the Genus Catops. By ANDREW MURRAY, Esq., W.S. 3. On Gemmiparous Reproduction (multiplication) in Actinia dianthus. By THOMAS WRIGHT, M.D. (Living specimens were exhibited.) The author stated that Actinia dianthus, the Plumose Sea Anemone of Dalyell, was found on the shores of the Firth of Forth, generally on rocks which were uncovered by the sea only at very low tides. Its habitat was not extensive; it is gregarious, great numbers being frequently found in a very limited space. At Arran he had seen several hundreds closely aggregated together, clothing the roof of a wide low cave, and hanging down like so many membranous bags half filled with water. A similar colony had existed on the perpendicular surface of a single large stone opposite to the Baths at Seafield; and, again, another on the under surface of a large overhanging rock at Wardie. It had been a matter of question with the author, how the young of these Actinias, if ejected from the mouth, as in Actinia mesembryanthemum, troglodytes, bellis, and gemmacea, were able to attach themselves to the rocks, instead of falling down and being washed away by the tide. It was known that

Actinia mesembryanthemum, troglodytes, and bellis, were exceedingly prolific, Sir John Dalyell and Dr Cobbold having seen twenty or thirty produced at a single litter from the first species, and yet the number of very young Actinias found in situations where old specimens abounded was very small, and certainly bore no proportion to the number generated. The cave at Arran was very difficult of access, on account of its shallowness and the floor being covered by a pool of water; and the Actinias were only to be reached by assuming a posture which could not be maintained for more than a few minutes. A number were, however, obtained, which, being attached to sponges, were easily stripped from the rock, and with them were associated a great number of very small specimens. Not long afterwards the author noticed a number of young surrounding a large white dianthus in the Vivarium of a friend at Leith, and was told that the Actinia, while moving round the tank, had left behind it small white bodies, which separated themselves from the foot or sucker and became young Actinias. Sir John Dalyell had described a similar mode of multiplication in Actinia lacerata, and Hollard in Actinia rosea (?) The former writer had observed that Actinia lacerata protruded from all parts of its foot, stolons or suckers, which became detached, and presently put forth tentacles, and were developed into minute Actinias. After reading Sir John Dalyell's account of Actinia lacerata, Dr Wright was anxious to ascertain whether there might not be included in the prolongations separated from the foot, either true ova or germs, or some tissue specialized for the production of young. In the hydroid zoophytes, such as Hydra, Coryne, &c., the walls of the body consisted of three elements or layers,-a dermal or integumental, an areolar or muscular, and a mucous or intestinal layer; and when gemmation took place in these animals, it occurred by the protrusion of a simple diverticulum or sac from the canal of the body, formed of all the three elements. This diverticulum was developed into a polype body, with mouth and tentacles like those of the polype, from which it pullulated; the two bodies having the digestive canal and all the tissues continuous with each other. In Hydra tuba, multiplication took place by stolons, which extended to some distance from the body before the new polype bodies sprouted from them, but in that case also a prolongation of the intestinal element passed through the stolon from the old into the new body. These new polypes were not young; their production was a simple increase of the individual, becoming afterwards a multiplication, either by accident, in some cases, or in others by a natural process of absorption. The structure of the helianthoid zoophytes or Actinias was more complicated in its development than that of the hydroid polypi, but it consists of the same three elements. The dermal coat was succeeded by the muscular element, which constituted the chief part of the external wall of the body and tentacles, and then passed inward to the stomach, in the form of septa or partitions, which suspended that viscus in the centre of the body, and divided the intervening spaces into numerous chambers. The mucous or intestinal element existed as a flattened sac or stomach, which appeared, when viewed edgeways, as a mere line extending down about half the centre of the body. The stomach communicated freely with the general cavity of the body. This cavity, which corresponded to the water-vascular system of the Acalephæ, was single below, but as it passed upward it formed a number of chambers divided from each other by the septa before mentioned, and finally communicated with the tentacles, each chamber terminating in the cavity of a single tentacle.

The whole of the general cavity and its chambers was lined with cilia, by which a constant circulation of the fluid was sustained, and the functions of nutrition, respiration, and excretion were all carried on simulta