SEX AND FERTILIZATION. 



109 



placed on the stigma or the operation deferred for a few 

 hours, but it is better to apply it as soon as the cap is re- 

 moved, as the minute grains will usually adhere and be in 

 position for absorption, or, more properly, germination, 

 when required. As the flowers do not all open at the 

 same time the cluster may have to be operated upon for 

 several days in succession, and when applying pollen to 

 those recently opened it is well to touch the stigma of 

 those operated upon the previous day with fresh pollen, 



in order to increase the 

 chances of success. Re- 

 peat these operations until 

 all the flowers, or as many 

 as may be required, are 

 fertilized, and then re- 

 move all * that remain 

 unopened. Tke cluster 

 should be protected by. 

 enclosing it in a bag made 

 of some kind of thin 

 fabric like Swiss muslin 

 or mosquito netting, for 

 if some such covering is 

 not used, insects may visit 

 the flowers, and interfere 

 with our work. When 

 the Grapes are ^ipe they 

 should be gathered, the seeds removed and planted in the 

 usual manner. In operating on the Grape as described, it 

 is presumed that the flowers are perfect, containing both 

 stamens and pistils as are usually found in the common 

 wild and cultivated varieties. But among the species of 

 the Grape indigenous to North America, an occasional 

 plant is found bearing both perfect and imperfect flowers, 

 wljile others produce only staminate flowers, the pistils 

 [nffmidevelqped or deformed. When perfect and im- 



fc. 47. 



IMPERFECT BUNCH OF GRAPES. 



