HYBRIDIZING AND CROSSING, 77 



MODE OF OPERATION. 



That we may proceed under standingly, let us examine 

 the flowers of the grape. Fig. 24 shows a flower as it is 

 expanding ; A shoAvs the five petals cohering to- 

 gether as they are lifted up and cast off by the 

 stamens ; the petals do not open, as in the rose, 

 lily, and most other flowers, but drop off with- 

 out expanding. Fig. 25 shows the flower after 

 the petals are gone ; the five stamens are now sur- Fi s- 24 - 

 rounding the center of the flower ; the little knobs at their 

 summits (B) are called anthers, which produce a fine dust 

 called pollen this is the fertilizing material 

 which we wish to control. Soon after the 

 flowers open, or the filling of the petals, this 

 pollen is carried by the air or insects to the 

 stigma (c), which is the terminal point of the 

 pistil, placed in the center of the flower. Fig. 25. 

 The surface of the stigma is covered with a viscid sub- 

 stance, to which the pollen adheres ; and so soon as the 

 pollen lodges here, it penetrates the stigma and passes 

 down through the pistil to the ovules or undeveloped seeds. 

 Now, this operation goes on without the assistance of man, 

 in all perfect flowering varieties of grapes ; but when we 

 wish to cross or hybridize a variety, we fertilize its stigma 

 with the pollen from another plant, and prevent the pollen 

 of the flower fertilizing its own stigma. To do this, so 

 soon as the flowers open, we cut off the anthers with a 

 small pair of scissors, leaving the flower as seen in Fig. 

 26 (D, stamens with the anthers removed), then take the pol 

 len from another variety, and dust it over the 

 stigma. This last operation is performed with 

 a fine camel's-hair pencil. Suppose we wish to 

 produce a cross between the Union Village and 

 the Delaware, which would certainly be very 

 desirable, as the foru ler is very large but not Fi. 26. 



