THE FRUIT. 51 



6. Vexillary; when one piece is much larger than the others, 

 and is folded over them, they being arranged face to face, as in 

 papilionaceous flowers. 



7. Induplicate; having the margins bent abruptly inwards, 

 and the external face of these edges applied to each other with- 

 out any twisting ; as in the flowers of some species of Clematis. 



8. Supervolute; when one edge is rolled inwards, and is en- 

 veloped by the opposite edge rolled in an opposite direction ; as 

 the leaves of the apricot. 



Of these forms of aestivation, the 4th, 5th, and 9th, are fre- 

 quently designated by the general term imbricate, that is, edge 

 overlapping edge. 



CHAPTER VIII. 



THE FRUIT. 



109. THE fruit appears to be the ultimate object and aim of the whole vegetable 

 organization ; accordingly, when this is perfected, the process of vegetation ceases, 

 the foliage withers, and the whole plant, if it be an annual, soon dies. But in the 

 fruit, provision is made for the reproduction of the species, so that it is justly 

 said to be ' the termination of the old individual, and the beginning of the new.' 



a. The fruit is, therefore, the most important part of the plant. Although it 

 does not, like the flower, serve to adorn the face of nature by the beauty of its 

 form and color, yet, besides its own peculiar office of perpetuating vegetable life, 

 it affords one of the principal means of subsistence to animals and to man. 



6. The fructification, in respect to time, is subsequent to the flower, is always 

 preceded by it, and, as has been sufficiently shown, is dependent upon it for its 

 maturity and perfection. After having imbibed the pollen fro*m the anthers, the 

 pistil, or its ovary, continues to enlarge, and is finally matured in the form of the 

 peculiar fruit of the plant. The fruit is, therefore, properly speaking, the ovary 

 brought to perfection. 



110. Such being the case, it follows that the fruit is constructed on the same 

 general plan as the ovary, and its structure may be inferred with nrnch accuracy, 

 by the examination of the latter at the time of flowering. In many cases, how- 

 ever, the fruit undergoes such changes in the course of its growth from the ovary, 

 as to disguise its real structure ; so that an early examination would be even more 

 safe in its results than a late one. 



a. For example, the oak-acorn is a fruit with but one cell and one seed, 

 although its ovary had three cells and six ovules. The change is produced by 

 5* 



