458 BOTANY. 



the stem in some, as the common hawthorn ; in others, spines are 

 superficial, or a growth from the bark, as in the rose-bush ; and 

 in other plants, as the common nettle, the spines are hollow, and 

 project when touched an acrid or poisonous fluid, nearly by the 

 same mechanism as is found in the fangs of poisonous serpents. 



Buds (gemmce) are bodies formed on the sides or summit of 

 the stems and branches of many plants, capable in many cases 

 of producing a complete plant, and containing in embryo the 

 leaves and flowers to be afterwards developed. Some writers 

 have held that the buds originate from the pith alone ; others 

 from the first circle of vessels surrounding the central medullary 

 portion ; others from the tender and new formed outer rings of 

 wood ; and others again, from the pith, wood, and bark con- 

 jointly. The buds are generally found in the axillae of the 

 leaves or terminal, and are the rudiments of the future leaves 

 and flowers; and their forming on removal from the parent plant 

 a multiplication of the individual, has given rise to the process 

 of grafting and budding in practical horticulture. The bulbs 

 or tubercles of the roots of many plants have the same prolific 

 power ; and several, such as the potatoe, are almost exclusively 

 propagated by the separation of the eye or bulb containing the 

 rudiment of a new plant. 



The ^flowers of plants comprise the organs by which fruc- 

 tification is accomplished, and those which surround and pro- 

 tect them. These organs are named the calyx or outer cup ; 

 the corolla or flower proper ; the nectary (ncctarlum) at the base 

 of some flowers secreting a sweet fluid ; the stamens (stamina) ; 

 and pistil (pistillum). The essential parts are the stamina 

 and styles, or the male and female parts of generation. The 

 sexes of plants had been noticed by observers prior to the time 

 of Linnaeus ; but this great man established the singular fact 

 by incontestible proofs. Most of the phanerogamous plants are 

 hermaphrodite, or possess stamina and pistils on the same flower; 

 but others are found on separate florets of the same plants, and 

 some on separate individuals. The pollen or fecundating pow- 

 der drops from the anthers on the pistillum, and the germs of 

 the future plants in the shape of seeds of various descriptions are 

 afterwards ripened in the ovary. The corolla or flower, protecting 

 the delicate parts within, is monopetalous, i. *. consisting of one 

 piece, or polypetalous, of many pieces. The colours and forms 



