XVII. HEREDITY, VARIATION, PLANT AND ANIMAL 



BREEDING 



Problems. To determine what makes the offspring of ani 

 mals or plants tend to be like their parents. 



To determine what makes the offspring of animals and 

 plants differ from their parents. 



To learn about some methods of plant and animal breeding. 



(a) By selection. 



(b) By hybridizing. 



(c) By other methods. 



To learn about some methods of improving the human race. 

 (a) By eugenics. 

 (b} By euthenics. 



SUGGESTIONS FOR LABORATORY WORK 



Laboratory exercise. On variation and heredity among members of a 

 class in the schoolroom. 



Laboratory exercise. On construction of curve of variation in measure 

 ments from given plants or animals. 



Laboratory demonstration. Stained egg cells (ascaris] to show chromo 

 somes. 



Laboratory demonstrations. To illustrate the part played in plant or 

 animal breeding by 



(a) selection. 



(&) hybridizing. 



(c) budding and grafting. 



Laboratory demonstration. From charts to illustrate how human char 

 acteristics may be inherited. 



HEREDITY AND EUGENICS 



Heredity and what it Means. As I look over the faces of the 

 boys in my class I notice that each boy seems to be more or less 

 like each other boy in the class ; he has a head, body, arms, and 

 legs, and even in minor ways he resembles each of the other boys 

 in the room. Moreover, if I should ask him I have no doubt 



249 



