STAMENS AND PISTILS. 43 



part multiplied from generation to generation 

 without change. 



But it is possible to cause deviations from 

 this law, by artificial means. 



If the pollen of one species is placed upon 

 the stigma of another species, the ovula will be 

 vivified ; and what is called a hylrid plant will 

 be produced by those ovula when they shall 

 have grown to be seeds. 



Hybrid plants are different from both their 

 parents, and are generally intermediate in cha- 

 racter between them. 



Reasoning from analogy it was formerly 

 thought that hybrids were sterile and could not 

 perfect seeds, experience however teaches that 

 this is not the case ; but in woody and other 

 plants where hybridisation has produced fine 

 varieties either of fruit or flowers, these varieties 

 are usually propagated by buds, cuttings, and 

 scions. 



The power of hybridisation will probably 

 when experience shall have matured and 

 science arranged more numerous results, be- 

 come the most correct test of botanical divi- 

 sions into genera. Great care is requisite in 

 making experiments on hybridisation to cut out 

 the anthers of one of the plants experimented 



