one single instance will you find it in opposition to the just ideas which science has given us, regarding the form of our globe, its magnitude, and its geology. There is, therefore, no physical error whatever in the Scriptures; and this transcendant fact, which becomes more admirable in proportion as it is made the subject of closer investigation, is a striking proof of the inspiration which dictated them, even to their least expressions."

157. Effects of Plants on the sand of the shore, and on the mud of rivers. Even at the present geological epoch, plants are concerned in the changes which are taking place in the soil of our globe. Many of them are beneficially employed in preventing the encroachments of the sea on the land, and in fixing the loose soil of our shores. The roots and underground stems of plants growing in these situations extend themselves widely in all directions in search of food, and thus become interwoven together so as to sustain the soil in a sort of basket-work, and consolidate the sands thrown up by the waves of the ocean. This is well seen in the case of the common bent or marram of our shores, and in some of the species of carex growing in the sand (fig. 167.) great sea-dyke which prevents the inundation of Holland is said to owe its stability in a great measure to the plants which grow upon it. Plants also increase the quantity of dry land by growing

The

in the mud deposited by rivers at their mouth. The quantity of mud carried down by rivers at the

present day is immense. Ansted states that the

Fig. 167.-Sand Carex (Carex arenaria), which with its underground stems and roots tends to consolidate the sands on the seashore.

Fig. 167.

Rhine at Bonn has been calculated to carry down 400 tons of solid matter per hour; and in the course of one year 7000 to 8000 millions of tons. The whole of the Delta of the Ganges, comprising 20,000 square miles, has been formed by that river and its tributaries. The quantity of mud carried down in the rainy season is so great, that it may be detected 60 miles from the coast. In the flood season, Major Rennel calculates that 450 millions of tons of mud are brought down by the Ganges daily. It is said that the muddy nature of the Amazon may be seen in the ocean at the distance of 300 miles from its mouth. This mud, when deposited, is speedily taken possession of by plants, and thus its stability is secured. Out of the deposits of the Rhine the greater part of Holland has thus been formed, and out of those of the Po a large portion of the Venetian territory has arisen. The papyrus of the ancients, the bulrush of the Scriptures (fig. 39, p. 52), has contributed in no small degree to form the Delta of the Nile; and the mangrove trees of the present day are thus contributing to the formation of new land in tropical countries. The seeds of the mangrove 'germinate before being detached from the branches, and when they drop into the loose mud in which the plant grows, they immediately become trees with singular stems (fig. 168), which divide near the base, and allow the water of the tide and the

rivers to flow freely between them. By the double agency of roots and germinating seeds there is thus a very rapid acquisition of new land, which, although swampy and unwholesome at first, ultimately may be made fit for the habitation of man.

"And such the mangrove, which, at full-moon flood,
Appeared itself a wood upon the waters,

But when the tide left bare its upright roots,

A wood on piles suspended in the air."

We find man himself pursuing the same system, and, whether he knows or not that he is imitating

Fig. 168.

nature, sowing ve

getation to secure and consolidate the mud which his piers and dams have detained, that he may gain a new territory from the waters, or to arrest the progress of the sands which might be blown by the wind so as to injure the land. Thus

does the marsh at length become a plain fitted for pasturage and agriculture, and the sands are consolidated and prevented from shifting.

Fig. 168.-Mangrove tree (Rhizophora Mangle) of the tropics, with its singularly divided stem, growing in the mud at the mouths of rivers.

II.-BEARINGS OF BOTANY ON ZOOLOGY.

158. The lowest tribes of plants become in an especial manner an object of study to the zoological inquirer, in consequence of the great similarity which exists between them and the lowest tribes of animals. For, while there are wide and marked differences between the higher plants and animals, the lowest members of these two kingdoms of nature approach so nearly, that it is difficult to tell where the one begins and the other ends. Thus sponges, which are considered as belonging to the lowest class of animals, were at one time looked upon as vegetables; and the common coralline (Corallina officinalis), has been lately transferred from the domain of the zoologist to that of the botanist. Some bodies which Ehrenberg represents as infusory animals, are now considered as being of vegetable origin.

159. The most careless observer must have noticed on the seashore many interesting productions, to all appearance of a vegetable nature, resembling plants in their form and habits;—some of them being arborescent in their mode of growth, and fixed by roots to rocks, stones, and other substances, in the same manner as sea-weeds. The opinions of naturalists were long divided concerning these bodies, and we are indebted to the work