Introductory. 17 



two beings can be begotten and developed in exactly the 

 same environment, and since environment always affects 

 tlie individual more or less, it follows tliat no two indi- 

 viduals .can be precisely alike. Variation in the olf- 

 spring may take place in any direction, as in the size or 

 color of the flower, the sweetness or juiciness of the 

 fruit, the prolificacy, the vigor (9), or the hardiness 

 (10) etc. It follows that in culture certain individual 

 plants or animals are more desirable to the cultivator 

 than others, because the individuals j)ossess different 

 CLualities. 



19. The Principle of Selection. Since the offspring 

 tends to resemble the parent or parents, we may gradu- 

 ally improv^e plants or animals in the direction of greater 

 usefulness by selecting the most desirable individuals 

 for reproduction. For example, by saving and planting 

 seeds from the plants that produce the finest petunia or 

 pansy blossoms, we secure finer flowers than if we gather 

 seeds without regard to parentage. 



20. Breeding in plants and animals is reproduction, 

 watched over and directed by man, with reference to 

 securing special qualities in the off'spring. It is based 

 on the principle that the peculiarities of the parent or 

 parents tend to be reproduced, and may be intensified, 

 in the descendants. But before we are prepared for the 

 study of breeding, we need to know something of the 

 principles of classification. 



21. Classification is the arrangement of the different 

 kinds of plants and animals into groups and families 

 based on individual resemblances. If we examine plants 

 as they are growing in nature, we may observe (a) that 



