238 THE FLOWER. 



whole logic of Systematic Botany upon a new and philosophical 

 basis. Our restricted limits will not allow us to trace its histor- 

 ical development. Suffice it to say, that the idea of the essen- 

 tial identity of the floral organs and the leaves was distinctly pro- 

 pounded by Linnaeus,* about the middle of the last century. It 

 was newly taught by Caspar Frederic Wolff, about twenty years 

 later, and again, after the lapse of nearly twenty years more, by 

 the celebrated Goethe, who was entirely ignorant, as apparently 

 were his scientific contemporaries, of what Linnaeus and Wolff had 

 written on the subject. His curious and really scientific treatise 

 was as completely forgotten or overlooked as the significant hints 

 of Linnaeus had been. In advance of the science of the day, and 

 more or less encumbered with hypothetical speculations, none of 

 these writings appear to have exerted any influence over the 

 progress of the science, until it had reached a point, early in the 

 present century, when the nearly simultaneous generalizations of 

 several botanists, following different clews, were leading inevitably 

 to the same conclusions. Ignorant of the writings of Goethe and 

 Wolff, De Candolle was the first to develope, from an independent 

 and original point of view, the idea of symmetry in the flower ; 

 that the plan, or type, of the blossom is regular and symmetrical, 

 but that this symmetry is more or less modified or disguised by 

 secondary influences, giving rise to various deviations, such as 

 those which we are soon to consider. The reason of the prevail- 

 ing symmetrical arrangement of parts in the blossom has only 

 recently been made apparent, in the investigation of the laws 

 of phyllotaxis (234) ; from which it appears that the general ar- 

 rangement of the leaves upon the leafy stem is carried out into 

 the flower. 



SECT. III. THE SYMMETRY OF THE FLOWER. 



436. A Symmetrical Flower is one which has an equal number of 

 parts in each circle or whorl of organs ; as, for example, in Fig. 

 256, where there are five sepals, five petals, five stamens, and five 

 pistils. It is not less symmetrical, although less simple, when there 



* " Principium florum et foliorum idem est. Principium gemmarum et 

 foliorum idem est. Gemma constat foliorum rudimentis. Perianthium sit 

 ex connatis foliorum rudimentis," etc. Philosophia Botanica, p. 301. 



