CALYX. 45 



laurel (Kalmia), the anthers are confined in ten cavities in the corolla; at the 

 proper season they are disengaged, and thrown forcibly against the stigma, by tlie 

 elasticity of the filaments. In Monoecious and Dioecious plants, where the sta- 

 mens are placed apart from the pistils in different flowers, the pollen is often con- 

 veyed to the pistil by insects in going from flower to flower in search of honey. 



93. Soon after the pollen falls upon the stigma, the outer coat 

 of each granule bursts (70, a) at one or more points, allowing 

 the inner coat to pass through it in the form of a tube. This 

 tube insinuates itself between the cells of the stigma, and 

 passes dowii between the loose cells of the style, extending 

 itself until it reaches the ovary, even when the style is of con- 

 siderable length. When these titbcs reach the ovary, they 

 direct themselves towards the ovules in different parts, and 

 enter the foramen, which at tliis time is turned towards the 

 base of the stylo, and brought in contact with its condvicting 

 tissue (83). 



94. As to the further action of the pollen grains, it is conjec- 

 tured that the molecules which they contain (69, a) are conveyed 

 by the tubes into each ovule, and that there developing them- 

 selves into new cells, and becoming fixed in their places, they 

 constitute the embryo of the future plant. All that is certainly 

 known, however, is, that the embryo first appears in the ovule 

 shortly after the pollen tube enters it. 



CHAPTER VII. 



THE FLOWER. 

 5 5. OF THE CALYX. 



95. The temi cabjz comes from the Greek, and signifies a 

 cup. It is applied to the outer whorl of the floral envelopes, in 

 reference to its common form and position. It is generally 

 green, but is sometimes colored, that is, it is of some other coloi 

 than green. It seems designed for the protection of the more 

 delicate organs of the flower in aestivation (in the bud). 



96. The divisions of the calyx are called sepals, which are 



