268 OF THE POLLEN. 



with a crest, as in many Erica:, and the 

 genus Pimis. See Mr. Lambert's splendid 

 work. 



The Pollen, or Dust, is contained in 

 the Anther, from which it is thrown out 

 chiefly in warm dry weather, when the 

 coat of the latter contracts and bursts. 

 The Pollen, though to the naked eye a 

 fine powder, and light enough to be wafted 

 along by the air, is so curiously formed, 

 and so various in different plants, as to be 

 an interesting and popular object for the 

 microscope. Each grain of it is commonly 

 a membranous bag, round or angular, 

 rough or smooth, which remains entire till 

 it meets with any moisture, being con- 

 trary in this respect to the nature of the 

 Anther; then it bursts with great force, 

 discharging a most subtile vapour. In 

 the Orchis family, and some other plants, 

 the pollen is of a glutinous nature, very 

 different from its usual aspect. See re- 

 marks on Mirabilis longiflora, Exot. Bot. 



v. 1. 44. 



The Stamens are changed to petals in 

 double flowers, and rendered useless. They 

 are often obliterated by excessive nourish- 



