orifice so that the water is forced into the interior aperture of the individual animals and passes out, as above described, by the exterior one. Food-collecting tentacles, therefore, would in this case be unnecessary, as their food would enter their mouths with the water. Providence thus taking care to compensate by this contrivance for the want of the ordinary in

struments.

Some of the Tunicaries are stated to have recourse to a singular mode of defence. When seized by the hand, contracting themselves forcibly, they ejaculate the water contained in their cavities, so as often suddenly to inundate the face of the fisherman, who in the astonishment of the moment suffers the animal to escape. If this be a correct statement, it proves that these animals are not altogether without some degree of intelligence, they know when they are assailed and how to repel

the assailant.

Having given some account of the most interesting of the aggregate Tunicaries, I am next to notice the simple ones.— In these the two orifices by which the sea-water is received and expelled are not at opposite extremities, but usually approximated, one being higher than the other and furnished with tentacular filaments. The animals are fixed to rocks, shells, and sometimes to sea-weeds, and are either sessile, or elevated on a footstalk: the sessile ones present a considerable analogy with the puff-balls, and the others with different funguses, as Clavaria, &c. They seem, especially Boltenia, which is covered with short stiff bristles, to approach the Echinidans. Nothing more is known of these animals, than that, like the others, they alternately absorb and expel the sea-water. The Cynthia Momus is remarkable for its changes of colour, being sometimes white, sometimes orange, and sometimes of a fleshcolour. As all this tribe are fixed, their history furnishes no other interesting traits.

Nothing is more striking than the infinitely diversified forms into which Creative Power has moulded the little frail animals, in this as well as the preceding classes, that are destined to inhabit, and numbers of them to illuminate, the wide expanse of waters occupying so large a portion of the globe we inhabit. When we survey, with curious and delighted eyes, the varied tribes that cover the soils of every aspect and elevation of that part of it that emerges from the fluctuating surface of the great deep, and which, instead of deriving their nutriment and means

1 PLATE IV. FIG. 1.

1

of life and breath from the waters, saline or fresh, live, and breathe, and are fed, by principles and elements communicated, either mediately or immediately, from the atmospheric ocean, an expanse that envelops uninterruptedly the whole of our globe, and which itself is fed and renovated by the constant effluxes of the great centre of irradiation; which also in its turn, as well as all the other orbs that burn and are radiant, and those that revolve around them and reflect their light, receive their all from Him, that GREAT AND INEFFABLE BEING, who gives to all and receives from none. But I lose myself, in infinite amazement; I shrink into very nothingness, when I reflect that such a miserable worm as I am, so fallen and corrupted, should presume to lift its thought so high, and lose itself in the depths of the unfathomable ocean of Deity. He has, however, commanded us to seek him, and assured us we shall find him if we seek him humbly and sincerely-he hath set before us his works and his word, in both of which he has revealed himself to us: and if our great object be to glorify him rather than ourselves, we shall collect the TRUTH from each, and shall find that they deliver, though each in a different language and style, the same mysteries; for they are the work and the word of the same Almighty Author, and must, therefore, if rightly interpreted, deliver the same truths, since they can no more contradict each other than he can contradict himself.

But let me endeavour to emerge from this ocean in which I seem to have lost myself, and, recovering my station upon terra firma, direct the attention of the reader to the lovely tribes that adorn every part and portion of this our destined but brief abode, I mean to the vegetable kingdom; we see how they cover earth, that not a spot can be found, of which in time they do not possess themselves, and that the more we extend our inquiries the more numerous are the individual species with which we become acquainted. This being the case upon earth, reasoning from analogy, we may conclude that something similar takes place in the ocean; that could our discoveries be extended under the sea as easily as they are upon land; could we traverse the bed and waters of the great deep with the same facility that we do the surface of the earth, we should find the numbers of vegetables that respire, in some sense, the air, fall short perhaps of those plant-like animals that respire the water. And could we examine the individual species of which this infinite host consists, and compare their organizations, we should find as great a difference in the instruments and organs

by which their life is supported and their kind continued, as in the animals themselves; and yet in all this diversity should trace a harmony and concatenation that would evidently prove the Wisdom that contrived, the Power that formed, and the Goodness that gave a living principle and breath of life to all these creatures, were each of them the attributes of an INFI

NITE BEING,

17*

CHAPTER VIII.

Functions and Instincts. Bivalve Molluscans.

HITHERTO in our progress from the lowest animal upwards, the mind has been perpetually submerged; not only every group, but every individual that we have had occasion to consider, has been an inhabitant of the waters, and to the great body of which a fluid medium is as necessary to life and action as an aërial one is to a land animal, but now we shall be permitted to emerge occasionally, for although the largest proportion of the animals forming the great class we are now to advert to, the Molluscans, are also aquatic, yet still a very considerable number of them are terrestrial, as a stroll abroad will soon convince us, when after a shower we find we can scarcely set a step without crushing a snail or a slug.

2

The term Molluscan' was employed by Linné to designate his second class of worms, which excluded all the shell-fish, and amongst real Molluscans included both Radiaries, Tunicaries, and Worms; it literally signifies a nut or walnut, and therefore seems more properly applied to shell-fish, than to animals which are defined as simple and naked. As now understood, it still comprehends a very wide range of animal forms, and it seems difficult to describe them by any character common to them all. Their Almighty Author, in the progress of his work of creation, linked form to form in various ways; he not only made an animal of a lower grade a stepping-stone towards one of a higher, and which formed a part of the ascent to man, the highest of all; but as the mighty work proceeded, he threw out on each side collateral forms that ascend by a dif ferent route, or begin one to a different order of beings. And this circumstance it is that has opened the door for so many systems and that diversity of sentiment with respect to the grouping of animals, which we meet with in the writings of the most eminent naturalists. Some proceed by one path and some by another, though the object of all is the same,

1 Mollusca.

2 Vermes.

unless some bias from a favourite hypothesis interferes and diverts them from a right judgment.

The organization of the animals of the Class we have just left, as we have seen, appears of a higher character than that of any of the preceding ones; traces of a heart appear; a nervous ganglion is detected between the mouth and anus, sending nerves to each; a regular respiratory system by means of gills becomes evident; but still the animal is furnished with no head, no eyes, and in numerous cases has no separate existence, but forms a branch of the general body-thus resembling a plant-from which it cannot dissociate itself and become an independent individual.

Indeed when we enter the Class of Molluscans, we find that the nearest affinities of the Tunicaries have likewise no head, and this circumstance appears to have induced Lamarck not only to separate them from the class as arranged by Cuvier, but also his whole family of headless Molluscans,1 of which he forms his two Classes of Cirripedes and Conchifers. The absence of a head from the animals of the bivalve and multivalve shells, is certainly a circumstance which, at the first blush, appears to justify their separation classically from the other Molluscans, but when we compare other characters, we shall find many that are common to both, particularly their nervous system, which is the same both in the Conchifers and Molluscans of Lamarck; for neither of these exhibit a medullary ganglionic chord, but only dispersed ganglions which send forth the requisite nerves; both have a double or bilobed mantle, gills on each side, and a heart and circulation. The Cirripedes indeed seem to be of a higher grade, at least their ner vous system is more perfect-since they have a longitudinal spinal marrow with ganglions, a mouth furnished with toothed jaws disposed by pairs, and jointed tendril-like organs about the mouth--and approaches near to that of the Annulose animal,* the Condylopes of Latreille. These, therefore, may be considered as properly entitled to the denomination of a Class; but should not be placed at a distance from the Crustaceans, to which Lamarck, with reason, thinks they make a near approach, as they are by Cuvier and Carus. In fact, they seem to have little to do with the bivalve Molluscans, except in being defended by more than one shell, and having no head.

I shall now mention the most prominent characters of those

1 Mollusca acephala.

3 Conchifera.

2 Cirripeda

4 Annulosa.