CHAPTER XVIII. 



THE FRUIT AND SEED-DISPERSAL. 



THE effects of Fertilisation extend in Flowering Plants beyond the 

 ovule or megasporangium to the carpels, and often also to the floral 

 receptacle. The mature Pistil or Gynoecium is called the Fruit. 

 Sometimes this term is applied in a strict sense to the ripened pistil 

 only. But it may be used in a more extended sense to include the 

 receptacle, or even other parts when they also undergo changes con- 

 sequent on fertilisation. This wider use of the term accords with 

 the definition of the Flower as a simple shoot bearing sporangia. 

 The Fruit would then be the whole of that simple shoot developed in 

 the interest of the ovules which it bears. 



According to the structure of the flower that produces it, the fruit 

 may comprise one carpel or more. The carpels may be separate or 

 united. They may in more specialised types be sunk down in the 

 tissues of the receptacle. Such differences of the gynoecium existed 

 already in the flower, and they remain as the fruit ripens, giving 

 variety to the construction of its different types. It would be possible 

 to analyse and describe the several kinds of fruits on the basis of their 

 morphological structure, and it is necessary to do this when the chief 

 purpose is systematic classification (see Appendix A). But another 

 method is to examine them from the biological point of view. The 

 function of the fruit is then taken as the basis of their study, and the 

 attempt is made to see how each type is fitted for its performance. 

 That is the aspect which will now be developed. 



The functions of the maturing fruit are the protection and nourish- 

 ment of the ripening ovules, and the dispersal of the seeds. It will 

 not be necessary to dwell upon the first, for it is so obvious. In 

 superior fruits the ovule, or ovules, are covered in by carpels, and 

 attached to them by their funicles. In this way effective protection 



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