562 



HISTORY OF ZOOPHYTES. 



ses qualities the most extraordinary. It is about 

 two feet long, covered with a very thin skin, 

 and its flesh composed of a gelatinous sub- 

 stance, which, however, within-side, is strength- 

 ened by a strong bone, of which such great 

 use is made by the goldsmith. It is possessed 

 of eight arms, which it extends, and which are 

 probably of service to it in fishing for its prey: 

 while in life, it is capable of lengthening or 

 contracting these at pleasure ; but when dead, 

 they contract, and lose their rigidity. They 

 feed upon small fish, which they seize with 

 their arms; and they are bred from eggs, 

 which are laid upon the weeds along the sea- 

 shore. 



The cuttle-fish is found along many of the 

 coasts of Europe, but .are not easily caught, 

 from a contrivance with which they are fur- 

 nished by nature ; this is a black substance, 

 of the colour of ink, which is contained in a 

 bladder generally on the left side of the belly, 

 and which is ejected in the manner of an ex- 

 crement from the anus. Whenever, there- 

 fore, this fish is pursued, and when it finds a 

 difficulty of escaping, it spurts forth a great 

 quantity of this black liquor, by which the 

 waters are totally darkened, and then it es- 

 capes by lying close at the bottom. In this 

 manner the creature finds its safety ; and men 

 find ample cause for admiration, from the 

 great variety of stratagems with which crea- 

 tures are endued for their peculiar preserva- 

 tion. 



CHAP. IV. 



OF THE POLYPUS. 1 



THOSE animals which we have described in 

 the last chapter are variously denominated. 



i Dr George Johnston, in his elegant work on British 

 Zoophytes, recently published, (Edinburgh, 1838, 8vo), 

 has adopted a new and seemingly excellent classification 

 of the zoophyte division of the animal kingdom. Where 

 a plant-like aquatic production, such as the Sponge, can- 

 not be discovered to be the work of, or connected with, 

 a polype, he excludes it from the zoophyte class, limit- 

 ing that term to polypes and their polypidoms. This 

 arrangement clearly defines the class. Of the zoophytes 

 thus distinguished, ho forms t\vo sub-classes, radiated 

 zoophytes, and molltiscan zoophytes. The characters of 

 these sub-classes are thus described : The radiated 

 zoophytes have a body contractile in every part, arid 

 symmetrical ; one aperture for receiving food, and ex- 

 polling its refuse ; and are propagated both by globules 

 and by eggs. The molluscan zoophytes have a body 

 non-contractile and non-symmetrical; separate apertures 

 for the reception of food, and expulsion of refuse ; and 

 sre propagated both by globules and eggs. The radiated 

 zoophytes are so named from the star-like disposition of 

 the calcareous matter of their polypidoms, while the 

 molluscan zoophytes are so entitled, because their polypi- 

 doms, unlike those of the preceding clas?, are living por- 



They have been called the Star-fish, Sea-net- 

 tles, and Sea-polypi. This last name has been 

 peculiarly ascribed to them by the ancients, 

 because of the number of feelers or feet of 



tions of the polypes they contain, as is the case with the 

 shelled molluscous animals, of which the lobster is an 

 example. The radiated zoophytes, again, are divided 

 into throe orders, the hydroida,(so called from some affi- 

 nity in their character to those of the many-headed 

 hydra, a fabulous serpent), the asteroida, (from the star- 

 like marks which distinguish them), and the helianthoida. 

 (a word which expresses their likeness to certain flowers, 

 as the anemone and marygold.) The molluscan class of 

 zoophytes has but one order, termed the ascidoida, of 

 which the chief distinctive characteristic is the vitality 

 of their enclosing crusts or cases. Of all these orders, 

 there are a number of families and species. Most of the 

 polypi form compound animals, attached to one another 

 by lateral appendages, or by their posterior extremity, 

 participating in a common life, while at the same time 

 they enjoy their individual and independent existence. 

 Many of this tribe are supposed to be gemmiferous, or 

 to extend the race by buds in the same manner as plants, 

 while others propagate their species by means of eggs. 

 In the lowest races of polypi, the distinctive characters 

 of animal life are so slightly developed, that, there is murh 

 difficulty in distinguishing them from the cryptogamic 

 families of the vegetable kingdom. The resemblance of 

 these animals to plants consists in this, that from the egg 

 is formed a bulb, which shoots up into a stem, and sends 

 oft' branches ; there is also a root, which, however, is 

 merely the organ of attachment, affording no nourish- 

 ment to the animals. Boing thus immovably fixed to a 

 particular spot, they have no other means of providing 

 themselves with food, but by their long tentacula, which 

 act as arms to convey the food to the mouth ; these 

 members only are capable of voluntary motion. The 

 vegetable structure of this class, long obtained for them 

 the name of animal plants. Some of them, however, 

 float about in the ocean, as the pennatula, or sea pens. 



About the year 1C99, Imperati and Gesner had re- 

 marked the animal structure of polypi or corals ; and 

 Peysonnell, in 1727, was the first who ascertained the 

 living inhabitants of those stony and horny structures, 

 and his discoveries have been confirmed by Trembley's 

 treatise upon the hydrie, published in 1740 ; and subse- 

 quently by Reaumur, Jussieu, Donati, Ellis, Boccone, 

 Degeer, Baster, Cavolini, Pallas, Linnaeus, and Cnvier. 

 All the animals of this class were placed by Limueus as 

 an order of his class Ferrnes, under the distinctive ap- 

 pellation of lithophytse. The sagacity of that t,reat 

 naturalist enabled him to form a superstructure, upon 

 which has been built the more improved, because better 

 known classifications of Pallas, Bruguiere, and Lamarck; 

 whose arrangement we mean to follow, as being more 

 comprehensive than that of Cuvier, who divides his class 

 polypi into two orders; the first of which embraces those 

 that are naked, and the second, such as live in polypi- 

 ferous masses, formed by the united labours of the com- 

 munity. These he subdivides into many families. 



Minute as the beings are which construct and inhabit 

 those stony masses called corals, they form one of the 

 largest, and undoubtedly the most singular of the whole 

 classes of animated being. Such is the enormous accu- 

 mulation of the stony envelopes formed by them in tro- 

 pical seas, that islands are produced, coasts extended, 

 and harbours blocked up by them. It was the opinion of 

 Lamarck, that it was these minute beings who originally 

 formed the calcareous strata of the globe. 



In contemplating the structure of the polypi, the hy. 

 dra, for example, we find their nutritive organs the sim- 

 plest of all possible forms ; consisting of a mere stomach 

 adapted to receive and digest food, without any other 



