STRUCTURE OF FLOWERS. 101 



plant — as, for example, mutilations owing to culture, the 

 unequal action of light, the pressure of neighbouring 

 bodies, &c. — then the irregularities are purely accidental ; 

 when, on the contrary, it results either from the mode 

 of development of the neighbouring organs, or, what is 

 more frequently the case, from the disposition of the 

 flowers, either with regard to each other or to the stem, 

 then the irregularity is constant, and the flower only 

 presents its natural state in very rare cases, and which 

 may, in their turn, be called accidental. 



The disposition of the flowers is, of these causes in- 

 herent in plants, the one of which we are the best 

 able to appreciate the effects. Thus, for example, when 

 they are near together, either in compact spikes or ra- 

 cemes along the axis, or in heads or umbels, the inner 

 or upper part of the flower, i. e. that which is nearest 

 the axis, is restrained in its development by the pressure 

 of the flowers against the axis or against each other ; 

 whilst the other side is more at liberty; whence it 

 results, that there is sometimes a complete or incomplete 

 abortion of some of the parts bordering upon the axis, 

 and the development of the opposite side ; sometimes a 

 more lengthened and complete union of the parts in the 

 neighbourhood of the centre, whilst those on the oppo- 

 site side are more free ; sometimes a union of the two 

 facts which I have mentioned. 



The general result of the pressure is counterbalanced, 

 sometimes even disguised, by another cause : viz. in a 

 flower when one of the parts of a verticil is entirely or 

 partly abortive, the corresponding part of the neigh- 

 bouring verticil takes a greater development than usual, 

 because it gains advantage either from the place or 

 nourishment which the other would have made use of; 

 whence it results, that it is extremely rare that the irre- 

 gularity of one of the floral organs does not produce an 



