BRITISH PLANTS. 11 



appropriated to its elongation and to the development of additional 

 fibres, and better to enable the stem to support the ever-increasing 

 Tveight above, a quantity is deposited in the cells and vessels about its 

 centre; and, lastly, it is secreted in great profusion by the new wood 

 and bark to form cambium, and to nourish, in the spring, the newly- 

 opening buds, until the roots are called into activity. 



The leaves, as has been before observed, are flat expansions of the 

 bark. They are usually supported upon foot-stalks, and consist of a 

 principal vein or mid-rib, whose ramifications form a sort of net-work, 

 the interspaces of which are filled with cellular tissue. And then, 

 better to protect their juices from excessive evaporation, the whole is 

 covered with a thin skin or cuticle, studded with innumerable minute 

 orifices (stomata), which open and close in conformity to the vicissi- • 

 tudes of the climate, and serve to regulate the amount of exhalation, 

 &c. They are to a plant what the stomach is to an animal ; for as 

 the food taken into the stomach of the latter undergoes a series of 

 chemical actions, its nutritive chyle being separated and taken up by 

 the lacteal vessels, and thence, by means of the thoracic duct, to the 

 blood-vessels, wherein it circulates and ministers to the growth and 

 sustenance of the whole body; so the food conveyed into the leaves 

 of a plant is also subjected to chemical action. By the agency of 

 light its water is decomposed, and the superfluous portion (m some 

 plants about four-fifths of the whole quantity introduced) passed off 

 by exhalation ; and the remainder, after receiving the necessary con- 

 stituents from the atmosphere, is returned in the shape of proper juice, 

 through the veins of the leaves to those of the bark, and thence by the 

 medullary rays to every part of the structure. 



BRITISH PLANTS: 



WITH OBSERVATIONS ON TIIEIK CULTURE. 



BY W. JOHNSTONE, ESQ., UAI.I.YKII.BHG JlOUSE. 



Perhaps in these few remarks there may be nothing very new ; and 

 we are convinced that the flowers selected are not the only ones de- 

 serving of attention, if, indeed, many others are not much more so ; 

 but they are simply selected because with them we have some small 

 acquaintance, and with a hope that, by making a commencement, 

 deficient of merit though it be, to induce others, more capable and 

 better qualified, to come forward with their pens in behalf of the very 

 lovely floral beauties of this our own dear sea-girt isle. 



I am convinced that many rich gems might be added to the garden 

 parterres from our meads, marshes, and mountains, which are heed- 

 lessly pulled and cast away by some rustic wanderer, or bloom un- 

 noticed in the habitations of those birds of the waste, the bittern and 

 ptarmigan. 



If many a native flower that now springs up, blooms, and withers 

 away, unheeded and imcared for, were transferred to the soil of the 

 garden, where art, with her fostering hand, would be ready to assist 



