NATURAL CLASSIFICATION. 51 



themselves, the sepals not being joined to 

 each other or to the petals, the petals not 

 being joined to each other or to the stamens 

 or pistils, and so on. De Candolle assigned 

 the highest place to the Crowfoot or Butter- 

 cup family and the lowest to the Grass fam- 

 ily. This sequence is essentially maintained 

 at present. Of course the genera and the 

 species of plants are the same in any system 

 of classification. Classification is simply a 

 method of arranging them. 



The most general division of the vegeta- 

 ble kingdom is into flowerless and flowering 

 plants, — Cr3rpt ogams and Phenogams. We 

 will exclude the cryptogams from our con- 

 sideration, as we have already discussed their 

 provisional arrangement. Phenogams may 

 be divided into inside-growers or one-seed- 

 leaved plants, — Endogens or Monocotyle- 

 dons, — and outside-growers or two-seed- 

 leaved plants, — Exogens or Dicotyledons. 

 Excluding the endogens, we find that the 

 exogens are most readily subdivided upon 

 characters of the floral envelopes : the indi- 

 viduals fall under three divisions, — Apet- 

 alae, Gamopetalae, and Polypetalae. These 

 terms find an explanation on page 35. Each 

 of these divisions contains its natural orders 



