FLOWERS AND FRUITS 153 



Variation in Seedlings. 



As a general rule the seeds produced by plants 

 which have been fertilised by pollen from another flower 

 of the same species, that is to say cross-fertilised, 

 yield more vigorous plants than the seeds from self- 

 fertilised flowers. When cross-fertilisation takes place 

 between two plants of the same species, but possessing 

 some different characters, the. resulting plants usually 

 possess some of the characters of each parent. Thus a 

 plant which bears white flowers, crossed with one which 

 bears red flowers, usually gives seedlings whose flowers 

 are, in various ways, marked with red and white. These 

 facts are made use of in the production of new varieties 

 of plants, both economic and ornamental. A plant, 

 possessing some one desirable character, is crossed with 

 another plant of the same species, with some other 

 desirable character, and the seedlings examined with 

 care ; those showing the required characters in the 

 greatest degree are selected, and the others rejected. It 

 must be remembered that only closely - allied plants 

 (plants of the same species), are as a rule capable of being 

 crossed with one another. Thus the various kinds of 

 peas, evening primroses, orchids, etc., can be crossed with 

 one another, but you cannot cross a pea with an orchid, 

 or an orchid with an evening primrose. 



These variations in plants are further made use of 

 when it is desired to produce a plant with some special 

 character, whether it be the shape or colour of the 

 flower, the size of the seed, or some particular feature in 

 the fruit. A large number of seedlings are raised frorn 



