THE FRUIT 127 



Dry fruits show greater variety. In some cases they 

 consist of one carpel only, many such fruits arising from 

 a single flower, as in the buttercup. This single carpel 

 may remain permanently closed, the seed being set free 

 only by its decay, or it may open along its front or both 

 front and back margins. In the latter case many seeds 

 are generally found inside. In other cases the carpels 

 while in the flower are joined together in their develop- 

 ment. When such a pistil is cut across it very generally 

 shows as many cavities as there are constituent carpels. 

 Sometimes the walls of the latter do not meet in the 

 centre, so that there is but one cavity. The seeds are 

 attached with hardly any exceptions to an outgrowth 

 of the edge of the carpellary leaf which constitutes a 

 placenta. There is a good deal of variety in this form 

 of fruit, as it varies with the number of carpels and 

 the ways in which they are united. Such fruits are 

 commonly called capsules. A singular variety of the 

 capsule is seen in the fruit of the wallflower and its 

 allies. Two carpels are joined together by their edges 

 and at the lines of union where a placenta can be seen 

 a membrane is developed quite across the cavity. 



Besides the dry fruits which open and let the seeds 

 out and those which retain the latter permanently, 

 another form is met with, consisting of several united 

 carpels, which separate from each other at maturity, 

 but each carpel continues to hold its seed. These 

 fruits are called schizocarps. 



A modification of the polycarpillary fruit is seen in the 

 nut. It has two or three constituent carpels and the 

 young fruit shows as many cavities as carpels. In 

 development, however, some or all of the partition walls 

 become dried up and disappear, so that there is only one 

 cavity in the adult fruit and this seldom contains more 

 than one seed. It is associated with a very hard 

 woody wall. All these modifications of structure show 



