266 Frinciples of Plant Culture. 



Pollination should be performed twenty-four to forty- 

 eight hours after emasculation (-t-tl), the period depend- 

 ing upon the plant and the stage of development of the 

 flower at the time of the latter operation (151). Applying 

 the pollen on two consecutive days tends to insure success. 



The pollen is applied by placing an anther (144) con- 

 taining mature pollen in direct contact with the stigma 

 (145), or by removing some of the pollen upon the back 

 of the point of a penknife or by means of a camel' s-hair 

 brush, and carefully applying It to the stigma. A pin, 

 of which the head has been flattened by hammering, in- 

 serted in the end of a stick, forms a convenient tool for 

 this work. 



The best time for pollination in the open air, is often 

 in the early morning, since the atmosphere is then usually 

 still, and contains little pollen from other flowers, which, 

 if freely present in the air, may vitiate the results of the 

 pollination. 



443. The After-Care of Crosses. After the last pollina- 

 tion, the blossom should again be inclosed until fecunda- 

 tion is effected, which is indicated by a rapid enlarge- 

 ment of the ovary. The paper sack may then be replaced 

 by one of mosquito netting. This should be securely, 

 but not too tightly, tied about the stem of the pollinated 

 flower, to protect the inclosed fruit or seed-vessel from 

 injury during growth and maturity, as well as to render 

 it conspicuous. A label should be placed within the 

 sack, or tied on with it, giving the name of the variety 

 whence the pollen was secured. It is also desirable to 

 record all the operations and observations relative to the 

 crossing. 



