104 Nuttall's Introduction to Botany. 



« The infant plant, is for a while nourished with a ready 

 formed supply of nutriment contained in the mass of the seed, 

 or in the infant leaves, {cotyledons,) which it first produces. 

 The vortex of vitality, influenced more or less by external 

 causes is now destined to continue its operation as long as 

 the plant happens to live ; (for the death in the vegetable 

 kingdom, which we see take place in a tree or a shrub, is ever 

 the effect of accident, as we have already remarked, that 

 no race of vegetable beings continues to live for more than a 

 year.) 



" Plants, like animals, consist of fluids and solids. The sap, 

 almost similar to the venous blood in its functions, is com- 

 monly imbibed from the bosom of the earth by means of the 

 fibers of the root. When it first enters, its composition is 

 very simple ; it is propelled upwards by a system of tubes or 

 vessels, but is not prepared or elaborated by any thing like a 

 stomach, as in animals ; the fibres of the root perform this se- 

 lective office : but so involuntarily, that poisons to the vegeta- 

 ble structure, if present, are almost as readily absorbed as 

 matters of nourishment. The sap at length conveyed into 

 the leaves and green twigs is then exposed to the action of 

 the light and the air, admitted by vertical pores, as in the 

 lungs or gills of animals ; and here in its descending course, 

 it becomes prepared to supply all the solids and other pecu- 

 liar products which characterize each peculiar species of 

 vegetable. 



" The constitutions of plants are more variable, than those 

 of animals ; so that they are fitted, in great variety, to occupy 

 the whole surface of the earth. The arctic regions have 

 their peculiar tribes of plants, as well as the luxurious region 

 of the tropics, where frost is unknown. At one extremity of 

 the earth, or on the snowy summits of the loftiest mountains, 

 vegetation only actively lives about two months in the year ; 

 in this short period the dwarf productions of this region of ice, 

 flower and perfect their seed, or prepare a new generation of 

 buds, and then again fall into a state of dormancy, and com- 

 monly remain buried beneath their congenial snows. Within 

 the tropics, a region which may truly be termed the paradise 

 of plants, the utmost variety prevails. Within the compass 

 of a few leagues, thousands of species may be enumerated ; 

 while the whole Flora of Spitzbergen contains only about 

 thirty species, and all of these dwarf herbs. In the tropics, 

 trees and shrubs are almost as numerous in species as herbs. 



