1843.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



347 



slopes of rocks, and never to that towards the east, west, or north ; others, 

 on the contrary, grow only on those exposures, and never to the south. 

 Sometimes the position is varied according to latitude, and the shores inclined 

 towards the south, in temperate or cold countries, producing the same species 

 as the northern exposures of equatorial regions." Again, it is evident that 

 the duration of their existence is variable; some are but the creatures of an 

 hour, of a day, of a few months, falling off and disappearing according to 

 their nature, and to the climate to which they are subjected ; thus in the 

 colder seas, numerous tribes are cut off every winter to be renewed in spring. 

 Some continually throw off their parts, and thus new generations are pro- 

 duced, and these gemmules being carried away by tidal action, or by attach- 

 ing themselves to locomotive animals, cause such tribes to be more generally 

 diffused. But although, as Lamouroux remarks, many species are periodi- 

 cally destroyed, it must not be supposed that entire destruction takes place, 

 the matured portion of the compound body remaining, as a tree stripped of 

 its leaves, being reclothed with verdure in the ensuing spring, and still add- 

 ing to its strength and size by multiplication of its imperishable parts. In 

 tropical countries, where the heat is general, the polyps spread abroad over 

 the valleys and troughs of the deep, without reference to inclination, as in 

 colder seas, their nature and qualities being determined by the temperature 

 and depth. 



The present accepted term of polype is much too vague and undefined to 

 be rightly understood, being made to embrace many animals of higher orga- 

 nization ; thus, according to the present acceptation of the term, every plant 

 and every animal may be classed as polype — every organic body, whether 

 it be animal or vegetable, increasing by the multiplication of its parts. The 

 term polype ought, therefore, to be confined to those simple organic bodies 

 which act independently in their parts and quantities, so that on separation, 

 the several divisional parts, as in the hydneda and other species, they expe- 

 rience no loss of power in this division, but still continue their functional 

 operatii ns, being perfect results in their separate state, and perfect results 

 as one whole. On the other hand, there are species of coral and corallines 

 where life is in entirety as in shrubs, and some of these cannot be propagated 

 by slips or cuttings. 



Numerous species are, from their nature, confined to particular localities 

 of the water, or to certain depths ; others are generally, and some are uni- 

 versally, diffused, maintaining their form and qualities under every latitude ; 

 but with few exceptions, locality has a marked and determinate influence in 

 their organic structure, and in their qualities and quantities, which almost 

 invariably depend on food and temperatuie, in consonance with the 

 known laws governing all animated nature, for beneath all latitudes like 

 Causes produce like Effects; when the temperature and local and general 

 action similate, the results similate also. Thus the stony corallines and corals 

 abounding in eastern seas, are of similar conformation and character to those 

 dwelling within western and southern seas; and thus it is in the uniformity 

 of living species, there is a uniformity of matter produced by the functional 

 operations of life, the depositions of matter forming strata composed of 

 oceanic organic bodies and their decomposed particles, being the unerring 

 indication of the temperature under which they lived and propagated in 

 their generations. Thus the fixed or locomotive animals or animo -vegetables 

 which secrete lime, and by deposition age upon age, form hills and mountain 

 chains of calcareous matter and of solid limestone, (such, for instance, as 

 much of the British strata is composed,) make us acquainted with the primary 

 causes of effects produced, being unerring indications of the vast and wonder- 

 ful changes w Inch this planet has undergone, and which it must still undergo 

 ere the end of nature is accomplished ; such organic beings as are hourly 

 manifested to us. having of necessity existed and propagated within a medium 

 and beneath a temperature adapted to their habits and character ; thus it is 

 that every formation of chalk, oolite, ocean marl, and calcareous matter, 

 however remote from those latitudes in the present day, however far re- 

 moved, however high it may be elevated above the present level of the sea, 

 however changed and disguised by time or circumstance, must, while gene- 

 rating and perpetuating their species, have been beneath tropical and quiet 

 seas duri ng those ages requisite for the completion of so vast'a mausoleum. 



The calcareous polyps, comparatively speaking, are scarcely known in the 

 depths of northern seas; the delicate corallines are equally scarce in the 

 depths of tropical seas, species being most abundant in latitudes where there is 



warmth and tranquility; all in their growth advance towards the rays of light 

 and heat : but where the sun is nearly vertical, they extend themselves in every 

 direction, without reference to latitude and dip. The sponges, sea mushrooms, 

 millepores, and many species of madrepore, together with echini, sea worms, 

 and numerous other species, are seldom found at any considerable depth, 

 intense heat communicated through the shallow aqueous medium and re- 

 fracted from the calcareous bed, being most favourable to the full develop- 

 ment of many species, and essentially necessary to the existence of others. 

 In proportion to the degree of heat, so is the quantity of lime, soda, mag- 

 nesia, and other compounds. 



To those who have seen the splendid collection of corals in the British 

 Museum, I would observe, that in many of the beautiful specimens, such as 

 Astrea and Meandrina, they behold the skeletons alone. The beautiful con- 

 volutions of the one, and the star-like appearance of the other, were once 

 covered with their animo-vegetative covering, exhibiting varying colours, as 

 green, blue, purple, white, &c. ; the now empty cells were then replenished 

 with living juices circulating throughout the compound body ; the dendro- 

 phillia, sensitive to the slightest touch, contracted its beautiful flowery head ; 

 and Gorgonia, approaching nearest to terrestrial shrubs, interposing its dark 

 twigs, gave relief and additional interest to the fairy scene, mimicking the 

 fairest gardens of the earth; the sponge too, light and tremulous to the 

 touch, was then filled with a thick viscid juice, and many species, now rigid 

 as marble, while living, waved their branches to and fro as agitated by the 

 tides, or by the passing monsters of the deep. 



In all and through all, we find the link of animal and vegetable life to be 

 so finely drawn as to prove inseparable; the nature of the material may 

 differ, but the mechanical action of the one and of the other at all times 

 assimilates, and in both we observe a beautifully graduated scale of life, from 

 the simple spark or mere imputation, to the most elegant and complicated 

 form, from the simplicity of union of primary principles to the development 

 of innumerable proximate principles and atomic compounds. Philosophic 

 observers of polyps may discover in their elementary properties, actions, 

 and sensibility to external impressions, identifying their animal organization, 

 but the body formed is one body, and, in numerous genera, is governed by 

 one influence ; and in these, the act of the tentacula is extrinsical and invo- 

 luntary ; not depending on the will of matter placed within the cellular ca- 

 vity, but upon the internal filament which passes through and connects the 

 whole in place of nerves, or upon the vital fluid, whose action pervades the 

 whole. It is of no real importance to man to be assured that the lethophy ta 

 and keratophyta are animal or vegetable ; the great and important question 

 is, what part do these minute developments of living action, fixed or loco- 

 motive, simply gelatinous, or converting into stone, perform in the economy 

 of nature ? From whence is derived the material of the animal or vegetable 

 body ? The important part they perform in giving increase to the earth and 

 to the most ponderable bodies of which it is composed, is manifest at every 

 step we tread, in every region of the waters ; the simply gelatinous and al- 

 buminous animals attach themselves to every consolidated substance, and 

 propagate like the grass of the field, thus ere the oyster has attained matu- 

 rity, its calcareous covering becomes the basis of a world in miniatuie: the 

 rock, the mineral body, and the ocean bed are concealed from observation by 

 the incrustation of countless myriads ; the waters teem with animalcula?, 

 witli numerous organic species, destroying, or becoming the prey of others : 

 as local influences determine, so they propagate or are destroyed ; and, fa- 

 voured by heat and quietude, so they diverge into species, and exhibit new 

 phenomena. 



In my next I shall proceed to consider the importance of the lime secreting 

 polyps in the economy of nature, and the results manifest in all parts of the 

 earth. 



H. G. M. 

 ( To be continued.) 



Life-Preservers at Sea.— Experiments have lately been made at Leith 

 harbour on a newly-invented safety cape, which may be worn, and thus pre- 

 serve a person from the danger of drowning in any depth of water ; and like- 

 wise a pillow inflated with air. Two persons jumped into the sea thus pro- 

 tected, and exhibited several m«ns of preserving the lives of shipwrecked 

 mariners. 



47* 



