144 CALENDAR AND INDEX. 



mode of multiplying the individuals when obtained Hence 

 there are two great objects which the cultivator should aim 

 at, viz Amelioration and Propagation. 



In planting seed for the purpose of procuring improved 

 varieties, care should be taken not only that the seed be 

 selected from the finest existing kinds, but also that the 

 most handsome, the largest, and the most perfectly ripened 

 specimens should be those that supply the seed. A seedling 

 plant will always partake more or less of the character of 

 its parent, the qualities of which are concentrated in the 

 embryo, when it has arrived at full maturity. As this sub- 

 ject has been already discussed in the second part of this 

 work, page 133, 1 shall direct the reader's attention to the 

 operation of Cross Fertilization. 



This is effected by the action of the pollen of one plant 

 upon the stigma of another. The nature of this action is 

 highly curious. Pollen consists of extremely minute hollow 

 balls or bodies ; their cavity is filled with fluid, in which 

 swim particles of a figure varying from spherical to oblong, 

 and having an apparently spontaneous motion. The stigma 

 is composed of very lax tissue, the intercellular passages of 

 which have a greater diameter than the moving particles of 

 the pollen. "When a grain of pollen comes in contact with 

 the stigma, it bursts, and discharges its contents among the 

 lax tissue upon which it has fallen. The moving particles 

 descend through the tissue of the style, until one, or some- 

 times more, of them finds its way, by routes especially des- 

 tined by nature for this service, into a little opening in the 

 integuments of the ovulum or young seed. Once deposited 

 there, the particle swells, increases gradually in size, sepa- 

 rates into radicle and cotyledons, and finally becomes the 

 embryo, the part which is to give birth, when the seed is 

 sown, to a new individual. Such being the mode in which 

 the pollen influences the stigma, and subsequently the seed, 

 a practical consequence of great importance necessarily fol- 

 lows, viz., that in all cases of cross fertilization, the new 



