THE CLASSIFICATION OF PLANTS 2159 



Natural Orders Classes, with Examples 



Stamina perigyna 6 (Eleagni, Proteae, Lauri, Poly- 



Stamina hypogyna 



Monopetalae 



Corolla hypogyna 



goneae) 

 7 (Plantagines, Amaranthi) 



8 (Scrophulariae, Solaneae, Gen- 

 tianeae) 



Corolla perigyna 9 (Ericae, Campanulaceae) 



Corolla epigyna, antheris con- 10 (Cichoraceae, etc.) 



natis 



Corolla epigyna, antheris dis- 11 (Rubiaceae, Caprifolia) 

 tinctis 



Polypetalae 



Stamina epigyna 

 Stamina hypogyna 



Stamina perigyna 



Diclines irregulares 



Following this step in systematic 

 Botany comes the very important 

 contribution of Augustin Pyrame de 

 Candolle (Fig. 2066) who, in his 

 " Theorie Elementaire de la Botan- 

 ique", first published in 1813, gave 

 to the science of comparative morph- 

 ology its first principles in his theory 

 of symmetry, that is to say the 

 doctrine that the nature of an 

 organism is expressed in the plan by 

 which the positional relations of all 

 its parts is manifested. The uncover- 

 ing of this plan from beneath the 

 effects of abortion, degeneration and 

 adhesion which obscure it, he con- 

 ceived to be the rule for the deter- 

 mination of true affinities. All plants, 

 he maintained, have the same physi- 

 ological functions with slight modi- 

 fications and therefore the vast 

 diversity of form displayed depends 

 only on diversities in the morpho- 



2N 



12 (Araliae, Umbelliferae) 



13 (Ranunculaceae, Papaveraceae, 



Gerania, Malvaceae, Cruci- 

 ferae) 



14 (Saxifragae, Rosaceae, Legumi- 

 nosae) 



15 (Euphorbiae, Urticae, Amen- 

 taceae, Coniferae) 



Fic. 2066. — A. P. de Candolle. Photo- 

 graph supplied bv courtesy of ilie 

 Wellcome Historical Medical 

 Museum. 



