814 APPLICATION OF PRINCIPLES. 



plant to the stigma of another, nevertheless requires 

 to be guarded by some precautions. In the first 

 place, it is requisite that the flower whose stigma 

 is to be fertilised should be deprived of its own 

 anthers before they burst, otherwise the stigma will 

 be self-impregnated, and although superfoetation is 

 not, by any means, impossible, yet it is not very 

 likely to occur. Then, again, the application of the 

 stranger pollen should be made at the time when the 

 stigma is covered with its natural mucus ; if not, the 

 pollen will not act, either in consequence of the 

 necessary lubrification of itself being withheld, from 

 the stigma being too young, or because the stigma, 

 from age, has lost its power of receiving the action 

 of the pollen. Neither should the stigma be in any 

 way injured after fertilisation has apparently taken 

 place. The art of fertilisation consists in the emission, 

 by the pollen, of certain tubes of microscopical tenuity, 

 which pass down the style, and eventually reach the 

 young seed, with which they comein contact ; and, un- 

 less this contact takes place, fertilisation misses. Now 

 the transmission of the pollen tubes from the stigma 

 to the ovule, through the solid stjle, is often very 

 slow, sometimes occupying as much as a month or six 

 weeks, as in the Misletoe. 



Those who occupy themselves in attempts at 

 improving the quality of cultivated plants should be 

 aware of this : namely) that the real quality of either 

 the fruit or the flower of a seedling cannot be ascer- 

 tained when they are first produced ; for it is only as 

 plants advance in age that the secretions necessary 



