INTRODUCTION. 



xxiii 



but more delicate ; the anther^ a two-celled body- 

 surmounting the filament, and, when mature, 

 usually bursting longitudinally, and allowing an 

 escape to the pollen, a light dust-like substance, 

 which is the fructifying principle of the flower. 

 Within the stamens, and occupying 

 a central position in the flower, is 

 the pistil, which also consists of three 

 parts, the germen, the style, and the 

 stigma: the germen or ovary, is a 

 hollow case at the base of the pistil 

 enclosing the seed, and finally be- distil. 

 coming the fruit ; the style is the column which 

 rises from the ovary and supports the stigma 

 or summit of the pistil. The stigma differs 

 from all other parts of the plant, in not being 

 covered with cuticle : it generally has a moist 

 surface for the purpose of arresting the particles 

 of pollen, which convey the fertilising principle 

 through the tubes of the style to the ovary. 

 The filament and style are not always present, 

 and in this case the anther and stigma are said 

 to be sessile, or sitting. The calyx and corolla 

 are not essential to the perfecting of seeds ; but 

 unless stamens and pistils are present, either in 

 the same or different flow^ers, no fruit can be 

 matured. On the number, relative lengths, 

 combinations, and position of these essential 

 organs, Linnaeus founded his Artificial System 

 of the arrangement of plants, the class being 

 for the most part decided by reference to the 

 stamens, the order being dependent on the pistils. 

 It is now unfortunately too much the custom to 

 decry the system of Linnaeus, and to speak of 

 his time as the dark age of botany ; " but its 



