CHAPTER I.

INTRODUCTORY.

"A box full of shells!" said Charles to his sister Lucy, who was looking over her treasures with great attention. "What can you want so many little shells for?"

"This box and its contents are the gifts of my cousin Jane," replied Lucy: "she said that I might have her whole collection, if I could find any pleasure in looking at shells without knowing anything about them. But I am not _quite_ ignorant of the subject."

"Shells are pretty enough," said Charles; "but how troublesome to distinguish the differences between each kind! I like plants better than shells."

[Sidenote: MULTIVALVES, BIVALVES, UNIVALVES.]

"Probably because you are better acquainted with plants," observed his father, Mr. Elliot, who had just entered the room: "however, the great naturalist, to whom you are indebted for your knowledge of plants, did not consider shells as objects beneath his attention."

"You mean Linnæus," said Lucy; "then he, I suppose, separated shells into the three different divisions--_Multivalves_, _Bivalves_, and _Univalves_."

"You are right, Lucy," replied her father.

"Pray show me some bivalve shells," said Charles; "I want to know their forms. A _bivalve_ is a shell with two openings, as I should imagine: yes, I see that I am right, for you have given me an oyster and a cockle."

"Here are also _Venus_, _Tellìna_, _Donax_, _Arca_, and _Pinna_," observed Mr. Elliot, "all very easy to distinguish."

"'The anchor'd pinna and his cancer friend,'"

repeated Charles. "So the _Pinna_ is a bivalve; but what has _Venus_ to do with the matter?"

"That is very easy to understand," said Lucy: "the genus called by her name is remarkable for beauty."

"Now, Charles," said Mr. Elliot, "do you clearly comprehend the verse that you have just repeated?"

[Sidenote: THE PINNA AND THE CANCER.]

"I have heard that the _Pinna_ is a shell-fish, attended by a _crab_, 'his cancer friend;' but why it is called _anchor'd_ I do not know, but _cancer_ is Latin for crab."

"Here is a species of _Pinna_," said his father, opening a cabinet; "and these silken threads are the means by which it fastens itself to the rocks. The animal is provided with a long foot, with which it draws out the threads, or _byssus_. The _Pinna_ is sometimes called the silk-worm of the sea. Lucy, do you know a univalve shell?"

"Oh yes, many!" replied Lucy, "here are rock-shells, cowries, limpets, and cones. I know the difference between a cowry and a cone; but I am not yet acquainted with a multivalve shell--will you show me one?"

"_Chiton_, or coat of mail, is a good example," said Mr. Elliot; "_Pholas_ is another genus of the same division; it has the appearance of a bivalve. In the _Chiton_ are several _lamina_, or plates, which are connected by a membrane while the living animal is in the shell; the membrane is pliant, and the inhabitant has the power of contracting itself into a ball, when it would avoid injury, like the insect millepes, that we find under stones in damp places. (Plate 2.) The curious barnacle-shell, _Lepas_, is another multivalve." (Plate 1.)

"I think we cannot have a more agreeable pursuit for our leisure hours," said Lucy, "than the study of shells. One can bring them out or remove them so easily, that they can cause little inconvenience, which garden-pots often do in town; and then the plants are almost sure to die, whatever care I take of them."

[Sidenote: LAMARCK'S SYSTEM.]

"Collections of shells are frequently to be seen in London," said Mr. Elliot, "which are intended for sale. There are now many places where shells are sold at moderate prices, and young collectors like yourselves can easily avail themselves of the means thus afforded, to obtain even a single specimen. While we remain in town you may visit the British Museum, and become familiar with the rare species of each genus, of which there are many costly specimens. The arrangement adopted for that collection is Lamarck's. You will find the work of this celebrated naturalist on my shelves; it is entitled, '_Histoire Naturelle des Animaux sans Vertèbres_.' The three last volumes contain the Conchology."

"It is in French and Latin!" exclaimed Lucy, as she opened a volume.

"Why do you both look so serious?" asked their father. "Are you not students in those useful languages? To what purpose do you learn a language if it be not with a view to reading the works of learned men, whose labours have opened a wide field of knowledge?"

[Sidenote: USE OF THE LATIN LANGUAGE.]

"But so many works on science are written in Latin," said Lucy. "Linnæus, however, has been translated, I know; and as for _British_ botany, we have our own authors in my own dear language."

"The Latin language being universally studied by men of science, it has become the medium of communication between the learned of most countries," observed Mr. Elliot. "I should consider a young person of your age, Lucy, very ignorant who could not read and understand the general style of Lamarck with the occasional aid of the dictionary."

"Do not be discouraged, brother," said Lucy, "my father will assist us: remember how frequently he helps us with our lessons now, provided we do our best. I am resolved to obtain some knowledge of shells this winter."

"A very good resolution," said Mr. Elliot; "and I predict that your usual delight on revisiting our favourite country dwelling will be somewhat increased next spring."

"Because I shall carry down my little collection with the pleasure of knowing more than I did last year."

"Our own coasts, rivers, and ponds afford a variety of shells. The hedge-banks, heaths, and other places, possess their inhabitants."

[Sidenote: PLEASURE OF SEARCHING FOR SHELLS.]

"Oh," exclaimed Lucy, "I quite forgot the very pretty snails I have so often admired on the heath on a dewy morning: why, we may learn conchology in the open fields as well as botany!"

"Well, then," replied Mr. Elliot, "to-morrow we will apply ourselves to the needful instruction. I must, however, remind you that I do not approve of any animal's life being taken away in order to obtain its habitation. Empty shells are to be found, which will serve perfectly well for specimens; and should the colour not be so bright as you could wish, you will have the delightful consciousness that your amusements have been free from cruelty, and that you have not destroyed the life of any living, harmless creature, in the pursuit of pleasure. Indeed there is as much or more gratification in searching among the rocks, or digging into the sea-sand, with a view to watch the animal in its natural place, as in possessing its empty shell: and who knows what grand discoveries you may both make!

"But I must leave you now--be ready for me after our usual dinner-hour."