CROSSING AND HYBRIDIZING. 73 



formed under the proper conditions, there are limits be- 

 yond which it cannot be carried. It is very common be. 

 tween two varieties of the same species, as two kinds of 

 apples, and it is sometimes successful between closely 

 allied species of the sam e genera, as the different species 

 of the gourd and melon families, but not between the 

 apple and the pear. When two varieties of the same 

 species are united the result is called a cross, but when 

 different species are crossed the result is known as a hy- 

 brid. 



The organs concerned in the production of seeds and 

 fruit are the stamens and the pistils, the former repre- 

 senting the male and the latter the female organs. They 

 are sometimes found in the same flower, as in the blooms 

 of the pear or cherry ; but in Indian corn the tassel rep- 

 resents the male portion, while the female is represented 

 by the silk and ear. Again, the pistils are in one plant 

 while the stamens are in another, as in the strawberry 

 some plants of which contain only male organs, and are 

 known as staminate, while others contain only the female 

 organs, and are called pistillate. The seeds of hybrids 

 are usually imperfect. Crosses have perfect seeds, but 

 when planted do not produce precisely the same kinds of 

 fruit. Some may be superior, while others are inferior 

 to the fruit of the parent trees. In order to have a better 

 chance of producing a superior kind by crossing, a num- 

 ber of flowers should be operated upon at the same time. 

 The first fruit of a tree, raised from a seed obtained by 

 crossing, may not be a fair specimen of what it will pro- 

 duce when a few years older. 

 5 



