TEUIT OK MATUEE PISTIL. 299 



effected ; but cases occur in which the fruit swells, and becomes to 

 all appearance perfect, while no seeds are produced. Thus, there are 

 seedless Oranges, Grapes, and Pine-Apples. When the seeds are 

 abortive, it is common to see the fruit wither and not come to 

 maturity ; but in the case of Bananas, Plantains, and Bread-fruit, the 

 non-development of seeds seems to lead to a larger growth and a 

 greater succulence of fruit. 



In order to comprehend the structure of the fruit, it is of great 

 importance to study that of the ovary in the young state. It is in this 

 way only tha,t the changes occurring in the progress of growth can be 

 determined. The fruit, like the ovary, may be formed of a single 

 carpel, or of several. It may have one cell or cavity, then being uni- 

 locular (unus, one, and loculus, box or cavity) ; or many, muUilocular 

 .(multus, many), etc. The number and nature of the divisions depend 

 on the number of carpels, and the extent to which their edges are 

 folded inwards. The appearances presented by the ovary do not, 

 however, always remain permanent in the fruit. Great changes are 

 observed to take place, not merely as regards the increased size of the 

 .ovary, its softening and hardening, but also in its internal structure, 

 owing to the suppression, enlargement, or union of parts. 

 In this way the parts of the fruit often become unsymmetri- 

 ■cal, that is, not equal to, or not a multiple of, the parts of 

 the flower ; and at times they are developed more in one 

 "direction than another, so as to assume an irregular appear- 

 ance. In the Ash (fig. 533) an ovary with two cells, each 

 containing an ovule attached to a central placenta, is changed 

 into a imUocular fruit with one seed ; one ovule, I, having 

 become abortive, and the other, g, gradually ex- 

 tending until the septum is pushed to one side, 

 becoming united to the walls of the cell, and the 

 placenta appearing to be parietal. In the Oak 

 and Hazel, an ovary with three cells, and two 

 ovules in each, changes into a one-celled fruit 

 with one seed. Similar changes take place in the 

 Horse-chestnut, in which the remains of the abor- 

 tive ovules are often seen in th e ripe fruit. In the ^s- 633. 

 Coco-nut, a trilocular and triovular ovary is changed into a one-ceUed, 

 one-seeded fruit. This abortion may depend on the pressure caused 

 by the development of certain ovules, or it may proceed from the 

 influence of the pollen not being communicated to all the ovules. 

 Again, by the growth of the placenta or the folding inwards of parts 



Kg. 533. Samara or Samaroid fruit of Fraxinus oxyphylla. 1, Entire, with its wing, a. 

 2, Lower portion cut transversely, to show that it consists of two loculaments ; one of 

 which, I, is abortive, and is reduced to a very small cavity, while the other is much enlarged, 

 and filled with a seed, g. 



