fe 



306 THE PHILOSOPHY 



The changes juft now mentioned are annual, and are ultimately 

 intended to fupply men and other animals with food. But plants 

 are fubjefted to changes of form from caufes of a more accidental 

 nature. Varieties or changes in the figure of plants are often pro- 

 duced by foil, by fituation, by culture, and by climate. 



A plant is compofed of the bark, the liber or inner circle, the 

 wood, and the pith. The calyx or cup, the carolla or flower leaves, 

 the ftamina, and piftils, are only expanfions of the bark, the liber, 

 the wood, and the pith. The petals of all flowers, in a natural ftate, 

 are fingle. But, when tranfplanted into gardens, many of them, 

 efpecially thofe which are furniflied with numerous ftamina, as the 

 anemone, the poppy, the peony, the ranunculus, the daify, the mari- 

 gold, the rofe, Ssc. double, or rather multiply their flower-leaves 

 without end. This change from fingle to double, or monftrous 

 flowers, as they are called, is produced by too great a quantity of 

 nutricious juices, which prevents the fubftance of the liber from con- 

 denfing into wood, and transforms the ftamina into petals ; and it 

 not unfrequently happens, that, when thefe double flowering plants 

 are committed to a poor foil, they become drier, are reduced to their 

 natural ftate, and produce fingle flowers only. Plants which inhabit 

 the valleys, when tranfported to the tops of mountains, or other ele- 

 vated fituations, not only become dwarfifh, but undergo fuch chan- 

 ges in their general flrudlure and appearance, that they are often 

 thought to belong to a different fpecies, though they are, in reality, 

 only varieties of the fame. Similar changes are produced when 

 Alpine or mountain plants are cultivated in the valleys. 



From culture and climate, likewife, plants undergo many changes.. 

 But this fubjeft is fo generally known, that to enlarge upon it wouH. 

 be entirely fuperfluous. We fhall only remark, that the older bo- 

 tanifts, when they perceived the fame fpecies of plants grow- 

 ing 



