PEDIGREED NURSERY STOCK 155 



pied by the pistil or pistils which finally develop into the fruit. The tip 

 of the pistil is soft and sticky so that it may catch and hold any of the 

 pollen grains which happen to alight upon it. The transfer of the pollen 

 to the pistil in this way is called pollination. 



After pollination occurs the pollen grain germinates and sends out a 

 sprout in a way analogous to that in which seed sprouts in a congenial soil. 

 The sprout from the pollen grain grows down through the soft substance 

 of the pistil till it reaches and fertilizes the egg cell. After fertilization 

 occurs the egg cell develops into seed. Commonly if no fertilization takes 

 place no seed is formed. Fertilization which is effected by pollen pro- 

 duced by the same flower as that which bears the pistil, or by the same 

 plant, is called self-fertilization. It should be noticed in particular that 

 in plants both the male and female parents are often united in one in- 

 dividual. That fertilization which is effected by pollen from another 

 plant, or speaking of cultivated varieties, from another variety, is called 

 cross-fertilization. Cross-fertilization is brought about under natural con- 

 ditions by the transfer of pollen from one plant to another through the 

 agency of winds or insect visitors. 



By the asexual method of reproduction plants are propagated by cut- 

 ting off or separating some part of the original plant such as bud, cutting, 

 scion, runner, off-set, etc., and growing it as an individual plant. Culti- 

 vated varieties of fruit are commonly propagated asexually. In fact it is 

 seldom that any of them are bred so that they will come true from seed 

 even when the seed is developed as a result of self-fertilization. For exam- 

 ple, among vines grown from the seed of Concord grape some will bear 

 white fruit, while others may bear black fruit. The fruit may be larger 

 or smaller, or earlier or later than that of the Concord. It is an inter- 

 esting fact that although thousands of vines have been grown from Con- 

 cord seed, there is no record yet of one which resembles the Concord 

 closely enough to pass under the Concord name. No cultivated varieties 

 of the apple are known which reproduce exactly true from seed. When a 

 new variety of fruit appears which possesses sufficient merit to make it 

 desirable to introduce it into cultivation it is commonly propagated 

 asexually. Thus all of the Concord grape vines which are growing today 

 have come directly or indirectly from the original Concord vine grown 

 from seed by Ephriam Bull in Concord, Mass., more than sixty years ago. 

 Likewise all of the Baldwin apple trees which are growing today have 

 come directly or indirectly from buds or scions taken from the original 

 seeding tree in Massachusetts which grew from seed more than. 150 years 

 ago. Plants which are grown by asexual methods of propagation com- 

 monly hold the distinguishing characteristics of the original plant, or at 

 least to such an extent that they can all bear the same name without 

 confusion. For example, when the word "Baldwin apple," is seen or 

 spoken it brings to mind the idea of a particular kind of fruit having cer- 

 tain distinguishing characteristics which are recognized by fruit growers 

 and fruit buyers throughout the country although the original Baldwin 

 tree perished 100 years ago. 



There are also cultivated varieties of plants propagated by seed 



