184 BRITISH PLANTS 



the scales which bear them enlarge and become woody. 

 Being closely packed together in a cone, and overlap- 

 ping, they cover the young seeds completely. By the 

 time the latter are mature and ready for dispersal, 

 the hard woody scales have become very dry and gape 

 apart, thus allowing the seeds to be blown out by the 

 wind. 



True fruits are developed from the ovary alone. Where 

 other parts of the flower contribute to its formation, the 

 fruit is said to be false. 



In classifying plants, we pointed out that two methods 

 were possible the morphological and the biological. The 

 same is true of fruits. We may base our classification 

 either upon the nature and development of the structures 

 involved in the formation of the fruit (morphology), or 

 upon the purposes which these serve (biology). Thus, all 

 the succulent fruits form a single biological group, serving 

 to attract birds, and the dispersal of the contained seeds 

 is effected by their agency. But morphologically they 

 differ very widely, the fleshy part being variously derived. 

 In the grape the entire wall of the ovary or pericarp 

 forms the succulent portion of the fruit ; in the plum only 

 a part of the pericarp is succulent, the rest forming a stone 

 which encloses the seed ; in the hip, haw, strawberry, and 

 apple it is the receptacle the portion of the flowering 

 axis upon which the flower rests which forms the fleshy 

 part of the fruit. There are thus many morphological 

 ways of attaining the same biological end, and in a 

 biological classification the end attained forms the basis 

 of grouping, and not the morphological means employed 

 to bring it about. 



Morphological Classification of Fruits. 



In a morphological classification the difficulty is to select 

 such morphological features or characters which will 

 enable us to separate fruits into natural and obvious 

 groups. For example, let us attempt to base a classifica- 

 tion upon the number and cohesion of the carpels, thus : 



1 . Fruits derived from an ovary of one carpel : 



(a) One-seeded. 



(b) Many-seeded. 



