152 



THE POPULAR EDUCATOR. 



RECREATIVE NATURAL HISTORY. 



BRITISH PEARLS AND PEAKLT SHELLS. 



IT would bo difficult to find, among the multitudes of strangely- 

 formed and deeply-interesting inhabitants of our lakes, rivers, 

 and the sea which girds our coasts, a wider field for study and 

 research than is presented by an examination of the habits and 

 peculiarities of the shell-bearing Mollusca. Whether we select 

 for investigation the tiny creature in his glass-like dwelling 

 among the green water-weeds freshly culled from the clear brook 

 (a familiar type of which is to be found in the Lymnea stagnalis, 

 the subject of the annexed illustration, Fig. 1) ; or dredge up 

 from the rock-fastnesses at the sea's bottom some stout and 

 strong sea-castle, like that inhabited by the Triton, figured in 

 the annexed engraving (Fig. 2) ; or search the grass and herbs 

 growing in some sheltered hedge-row, where the snails and other 

 land-shells love to dwell, we find the same admirable fitness and 

 marvellous adaptation to the position and conditions under which 

 each had existed : and notwithstanding that the one possesses 

 the power of supporting and carrying out the various functions 

 of existence in water far removed from the sea, the other beneath 

 the salt waves of the ocean, and the third in situations far re- 

 moved from water either fresh or salt, a perfect shell, exquisite 

 in form, admirable in design, and very nearly of identical com- 

 position, is secreted in each instance. Many of these terres- 

 trial shells are, notwithstanding the position assigned them by 

 nature, capable of assimilating elements productive of rich, 

 admirable, and varied colouring. The annexed sketch of Helix 

 hemastoma (Fig. 3) will servo to show this. Few of our readers 

 will have failed to observe the beauty of tint and variety of 

 shading to be found on the shells of the common banded and 

 golden-yellow snails of our hedges, lanes, and thickets. 



Few natural processes are more extraordinary and mysterious 

 than that by which colour and quality of product are produced 

 by living creatures, and even the lowest orders of plants. We 

 take a grain of wheat, the seed of the poppy, the nttir vomica, 

 and the deadly nightshade ; we prepare a suitable tub or other 

 vessel for them to grow in ; we furnish soil, water, heat, and 

 shelter ; and in due time, when the plants from each of these 

 seeds have arrived at maturity, we shall find that no two 

 will be alike either in colour of blossom, form of foliage, or 

 shape of plant. We go a step farther, and subject them and 

 their products to chemical analysis, and we find food suitable 

 for man associated with a pl,iiit-tnlk covered with a sheath 

 of pure flint in the wheat ; whilst the poppy, with its rich 

 scarlet tintu and soft stem, yields the useful alkaloid morphia ; 

 and the nux vomica furnishes to us the deadly poison, 

 $trychnia all these wondrous elements and compounds being 

 drawn from the one simple tub of earth, and the water with 

 which it was supplied. So it is with the shells of the earth, the 

 river, and the eo;t : by processos the nature of which we know 

 nothing, results of the most extraordinary nature and magni- 

 tude are brought about. Not only the spined and gaily- painted 

 shell of the coral reef, but the very reef itself, destined at some 

 time to form a home for man, is slowly but surely being built 

 up and massed together by the living labourer, who works by 

 laws far beyond our ken. The eggs of birds, too, are marvellous 

 in their form and colouring, and possess a crust or shell closely 

 resembling that of the shells we have been describing, both in 

 texture and component parts. Dealing with shells and, struc- 

 tures allied to them, we can easily pile such beautiful works of 

 an all- wise Creator together, apply fire and reduce them to lime ; 

 but with all our boasted skill in science and art, no human 

 power or ingenuity could, from the materials thus formed, cause 

 the building up of that which has been so readily torn down. 

 Pearls, after all, are merely lime which has passed through the 

 laboratory of that most wonderful of chemists, the shell-bearing 

 mollusk. For the early history of English pearls, and the sheila 

 which yield them, we must go back to a period when Britain was 

 known to other nations as a mere group of islands vaguely 

 known as the Cassiterides. This supposed group was, no doubt, 

 formed by the Scilly Islands and the projecting land of the coast 

 of Cornwall. This region was probably first discovered by a 

 band of Phrenician voyagers who were dispatched about 600 B.C., 

 by Pharaoh-Necho, king of Egypt (the same who slew Josiah, 

 king of Judah). These bold adventurers we~3 directed to set 

 sail from the Red Sea, to voyage round Africa, and enter the 

 northern seas by the Straits of Herculen, when they were to 



explore and investigate such countries as they might find, and 

 take note of all valuable productions. On the discovery of 

 the Cassiterides .by the PhoBiiicians, tin and probably pearlo 

 formed important objects for commercial enterprises; but the 

 situation of the new treasure-lands was for a long time success- 

 fully concealed by the fortunate discoverers. The Romans, 

 however, at length discovered the secret, and there appears little 

 doubt that the glowing accounts given of the fabulous quanti- 

 ties of pearls possessed by the inhabitants of " Baratanac," 

 or Britain, first led Julius Ceesar to plan his second invasion, 

 and decide on its capture and subjugation. That pearls were 

 the great and main attraction is proved by the fact of one of his 

 first offerings to the shrine of Venus Genitrix as a successful 

 conqueror being a shield or buckler covered with pearls from 

 his new possession. Pliny, in writing of this offering, says that 

 the pearls from Britain were of small size, devoid of lustre, and 

 very inferior to those of Eastern origin ; Tacitus also speaks of 

 them in much the same terms. It is fair, therefore, to infer 

 that the description of pearl known in those early days was 

 obtained from the common edible mussel (Mytilus edulis, the sub- 

 ject of the accompanying illustration, Fig. 4), which is only met 

 with at the mouths of tidal rivers where the water is strongly 

 impregnated with salt, or in the sea itself. An investi- 

 gation of the contents of these palatable bivalves will often 

 lead to the discevery of small pearls of little or no commercial 

 value. Some years since, when pearls formed an important 

 element in the prescriptions of medical men, they were far more 

 eagerly sought after than now. The common oyster of our 

 coasts is also occasionally found to yield small or seed pearla, 

 which are of value only to the curious. The great silk mussel 

 (Pinna nobilis, a representation of which is shown at Fig. 5, on 

 a reduced scale) is the largest bivalve shell found in our seas. 

 It not only produces a tuft or tassel of silk-like material, 

 known as tho"byssus," which is at times spun into gloves 

 and stockings, but is often found to contain coloured pearls of 

 considerable value. Some of these are of a steel-grey tint, 

 others are lead-coloured, reddish, and occasionally even black. 

 It is not to this shell, however, that we have to look for the 

 true precious pearl of Britain : that is produced by a shell 

 much larger than the edible mussel, bearing no silk, and dwelling 

 exclusively in running streams of fresh water. The rivers of Wales, 

 Ireland, Germany, and Switzerland have been long celebrated 

 for their pearl mussels. The Unto margaritifenis, as it is called 

 by naturalists, represented at Fig. 6 in the accompanying illus- 

 tration, is the true fresh-water pearl-shell. It has been found 

 measuring five inches and a half in length, and two inches and a 

 half in breadth across the valves ; but it is very rarely so large, the 

 great majority of specimens but little exceeding five inches long 

 by about two inches broad. Some curious information relating- 

 to Irish pearls was communicated by Sir Robert Redding, 

 through a Dr. Martin Lister, to the Philosophical Transactions 

 of 1673. He states that the rivers of Derry, Donegal, Tyrone, 

 Wexford, and Kerry contained tke pearl mussels, and that the 

 poor people in the neighbourhood cf the streams fished for 

 them during the warm weather preceding harvest, when there 

 was little water flowing, and that they made use of either their 

 toes, wooden tongs, or sharp-pointed sticks for dislodging 

 them from their retreats on the bottom or among the stones. 

 The sharp sticks were, ho says, thrust between the open valves 

 of the shells " as they lay in part opened, with the white foot 

 protruded like a tongue out of the mouth." He then states 

 as follows : " Some gentlemen of the country made great 

 advantage thereof ; and I myself, whilst there, saw one pearl 

 bought for fifty shillings that weighed thirty-six carats, and 

 was valued at forty pounds. Everybody abounds with stories 

 of the good pennyworths of the country, but I will add one 

 more. A miller took out a pearl, which he sold for four pounds 

 ten shillings to a man, who sold it 1'or ten pounds,, who sold it 

 to the late Lady Gleneally for thirty pounds, with whom I saw 

 it in a necklace. She refused eighty pounds from the late 

 Duchess of Ormond for it." 



Scotland, too, particularly in past times, had reason to boast 

 of the importance of her river pearls, the Tay, from Perth to 

 Loch Tay, being one of the richest streams. Captain Brown, 

 in recording the particulars of the Scottish pearl-fishing, says, 

 "The pearls sent from Scotland to London from the years 1761 

 to 1764 were estimated at ten thousand pounds' value." The. 

 Isle of Man, too, has had its river harvest, and a peculiar 



