210 ELEMENTS OF STUUOTURAL BOTANY. 



being a sub-division of the Dicotyledons. The Lichens, 

 also, are included in the Fungi. 



362. The whole question of botanical classification is 

 still in an unsettled state. For further information in 

 regard to the various modes that have been put forward, 

 the student must consult larger works. In the second 

 part of this book, whilst the classification of Gray (who 

 follows Bentham and Hooker) is followed in a general 

 way, those who prefer the second arrangement of the 

 Phanerogams as given above may easily make the 

 requisite change. 



' 363, Each of the Dioisiuns is sub-divided into a number _ 

 of Families or Orders ; each Order into a number of 

 Genera ; and each Genus into SpecieS. 



The names of the Orders as a rule have the ending 

 -aceoi, as : RanuneulaceoB, Bosaeem. These names are 

 adjectives agreeing with the noun Plantm understood, so 

 that they mean '! Rosaceous plants," " Ranunculaceous 

 plants," &c. 



364. A species is the sum of all the individual plants 

 whose resemblances in all essential respects are so great 

 as to warrant the belief that they have sprung from one 

 common stock. De Candolle has this statement : " We 

 unite under the designation of a species all those indi- 

 viduals that mutually bear to each other so close a 

 resemblance as to allow of our supposing that they may , 

 have proceeded originally from a single being or a single 

 pair." We may also speak of each one of these individual 

 plants as a species. , For example, you may say, after 

 finishing the first lesson of this book, that you have 

 examined a species of Buttercup, Mere difierences of 



