XIV INTRODUCTORY REMARKS. 



the majestic Palms, the Bananas and Baobabs of tropical climes from the 

 minute aquatics of our northern pools to the gigantic Victoria of the South 

 American waters from the parasitic fungus, only visible by the aid of the 

 microscope, to the enormous parasite discovered by Raffles in the Indian Archi- 

 pelago. 



It is interesting to trace the relation which all these plants bear to each other, 

 and the mode in which they are adapted to different climates and situations. 

 The lichens are propagated by spores (seeds) so minute as to appear like thin 

 dust, and so easily carried by the wind that we can scarcely conceive any place 

 which they cannot reach. They are the first occupants of the sterile rock and 

 the coral-formed island being fitted to derive the greater part of their nourish- 

 ment from the atmosphere and the moisture suspended in it. By degrees they 

 act on the rocks to which they are attached, and cause their disintegration. By 

 their decay a portion of vegetable mould is formed, and in progress of time a 

 sufficient quantity of soil is produced to serve for the germination of the seeds of 

 higher plants. In this way the coral island is, in the course of years, covered 

 with a forest of coco-nut trees. Thus it is that the most despised weeds lay the 

 foundation for the denizens of the wood; and thus, in the progress of time, the 

 sterile rock presents all the varieties of meadow, thicket, and forest. 



The Creator has distributed bis floral gifts over every part of the globe, from 

 the poles to the equator. Every climate has its peculiar vegetation, and the 

 surface of the earth may be divided into regions characterized by certain pre- 

 dominating tribes of plants. The same thing takes place on the lofty mountains 

 of warm climates, which may be said to present an epitome of the horizontal 

 distribution of plants. Again, if we descend into the bowels of the earth, we 

 find there traces of vegetation a vegetation, however, which flourished at dis- 

 tant epochs of the earth's history, and the traces of which are seen in the coal, 

 and in the fossil plants which are met with in different strata. By the labours 

 of Brongniart especially, these fossil remains have been rendered available for 

 the purposes of science. Many points have been determined relative to their 

 structure, as well as in regard to the climate and soil in which they grew, and 

 much aid has been afforded to the Geologist in his investigations. 



The bearings which Botany has on Zoology are seen when we consider the 

 lowest tribe of plants, such as Diatomacese. These bear a striking resemblance 

 to the lowest animals, and have been figured as such by Ehrenberg and others. 

 The observations of Thwaites on Conjugation have confirmed the view of the 

 vegetable nature of many of these bodies. There appear, however, to be many 

 productions which occupy a sort of intermediate territory between the animal 

 and vegetable kingdom, and for the time being the Botanist and Zoologist must 

 consent to joint occupancy. 



The application of botanical science to Agriculture and Horticulture has of late 



