THE NATURAL .-j.'STEM. 115 



cies with itb progeny of millions of plants ; the Eed Clover is 

 another; the Yellow Clover another; the Buffalo Clover 

 another. In like manner all the plants of the globe are 

 grouped into species, and this is the first step in classification. 



243. The second step carries us to the genus, which we 

 may thus define : A Genus is an assemblage of species which 

 are much alike ; especially in their flowers and fruit. Tlaus, 

 Flax is a genus made up of the several species mentioned 

 above, and other similar species. Clovee is a genus com- 

 posed of 150 species, some of which we have just mentibned. 

 Every one notices the resemblance between White Clover, 

 Eed Clover, &c. Pine is a genus, embracing as species 

 White Pine, Yellow Pine, Pitch Pine, Long-leaved Pine, and 

 many others. 



244. Individuals of the same species may differ somewhat 

 among themselves, and these differences constitute varieties. 

 Thus Apple-trees differ in their fruit, and there are hundreds 

 of varieties although only one species. Eoses differ in their 

 form, color, and fragrance of their flowers, forming many va- 

 rieties under each species. Probably no two plants of any 

 species were ever exactly alike. Sameness, or monotony, is 

 not a characteristic of Nature. 



LESSON XXX. 



THE NATURAL TSTEM. 



245. lis attempting to classify and arrange the genera of 

 plants, according to their natural resemblances and differ- 



343. Can you now define a genus ? Please illustrate your idea of a genus. 

 244. What is a variety ? Illustrate your meaning. 



