CH. VI.] THE FLOWER. 199 



pajDer, places them in a warm room for a day, collects 

 the pollen they emit, and presences it in sheet lead 

 in a cool diy place. M. Godefroy suggests that two 

 concave glasses, like those employed for vaccine "\-inis, 

 would be better. The globules of the pollen must 

 not be crushed. M. Haquin thinks the pollen of 

 one year mil be effective if preserved imtil the year 

 following. Mr. Jackson of Cross Lanes Xiu-ser}', 

 near Bedale, says, he has found the pollen of the 

 Rhododendron Smithii tigrinum retain its fertilizing 

 power even for twelve months. 



1(J. It is easy to discern whether impregnation has 

 been effected, as in such case the stigmas soon wither. 

 The stigmas which have not received the pollen 

 remain for a long time green and vigorous. 



" By the aid of the Stanhope lens," obsen^es Capt. 

 Thurtell, in a letter now before me, " 1 fancy I can 

 discover the seed of the pelargoniimi being closed 

 over in the space of four hours after impregnation." 



11. When double flowers are desired, if a double 

 flower should chance to have a fertile anther or two, 

 these should be employed for fertilization, as their 

 offspring are almost sure to be very double. 



\'Z. Many analyses of the pollen of various plants 

 have been made by chemists, ^^ithout throwing 

 any light upon hybridizing. M. Grotthus found the 

 components of twenty-six grains of the pollen of the 

 tulip were : — 



