372 MORPHOLOGY OF THE CARPEL. [BOOK i. 



they are completely united into an undivided body, as in 

 Pyrus, they are syncarpous. That syncarpous pistils are 

 really made up of a number of united carpels is easily shown, 

 as Goethe has well remarked, in the genus Nigella, in which 

 N. orientalis has the carpels partially united, while N. da- 

 mascena has them completely so ; in the latter case, however, 

 the styles are distinct. They and the stigmas are all conso- 

 lidated in a single body, when the pistil acquires its most 

 complete state of complication, as in the Tulip ; which is, 

 however, if carefully examined, nothing but an obvious mo- 

 dification of such a pistil as that of Nigella damascena. 



This important conclusion is deducible from the foregoing 

 considerations : viz., that, as the carpels are modified leaves, 

 they are necessarily subject to the same laws of arrangement, 

 and to no others, as leaves developed around a common axis 

 upon one or several planes. For no axiom appears more in- 

 contestable in botany, than that all modifications of a given 

 organ are controlled essentially in the same way, a,nd by the 

 same influences, as the organ itself in an unmodified state ; 

 and hence every theory of the structure of fruit which is not 

 reducible to that which would be applicable to the structure 

 of whorls of leaves is vicious of necessity. I shall proceed to 

 demonstrate the perfect accordance of the carpellary theory 

 of structure in every point with these principles. 



Let it be assumed that the placenta arises from the two 

 margins, either distinct or combined, of a leaf folded inwards. 

 When a leaf is folded inwards, its margins will point towards 

 the stem or axis around which it is developed; and in a 

 whorl of leaves such inflected margins would all be collected 

 round a common centre ; or, if the axis were imaginary, in 

 consequence of the whorl being terminal, would be placed 

 next each other, in a circle of which the back of the leaves 

 would represent the circumference. Therefore the placentae 

 will always be turned towards the axis, or will actually meet 

 there, forming a common centre; and, which is a conse- 

 quence of this law, if one carpel only, with its single pla- 

 centa, be formed in a flower, the true centre of that flower 

 will be indicated by the side of the carpel occupied by the 

 placenta. Proofs of this may be found in every blossom : 



