518 



BOTANY 



PART II 



very various form which are formed from the carpels (often together 

 with the persistent calyx and the floral axis) are called fruits, and 

 serve primarily to protect the developing seeds. In Gymnosperms 

 where the ovules are borne freely exposed on the carpels no fruits in 

 the strict sense can exist, since no ovary is present. Thus in Cycas, 

 Ginkgo, Taxus, Fodocarpus, Gnetum, and Ephedra we can only speak of 

 seeds and not of fruits. When, however, the carpels after fertilisation 

 close together as in the cones of some Gymnosperms and the berry- 

 like cones of Juni2)erus, a structure analogous to the angiospermic 

 fruit is formed, and the term fruit may be used. 



The Fruit (^-). — A great variety in the development of the fruit 

 in Angiosperms might be anticipated from the range in structure of 

 the gynaeceum described above. The product of the individual 

 carpels associated in such apocarpous gynaecea as those of the 

 Eosaceae will here be termed partial fruits or fruitlets, while 



e 



1' 



Fio. 486. — Modes of dehiscence of capsular fruits. A, B, Capsule of Viola tricolor before and after 

 the dehiscence ; C, poricidal capsule of Antirrhinvm majus (magnified) ; D, E, pyxidium of 

 Anagallis arvensis before and after dehiscence. 



the product of the whole gynaeceum will be spoken of as the fruit. 

 The hollowed-out or projecting floral axis bearing the carpels may be 

 included in the fruit. In the case of fruits resulting from syncarpous 

 gynaecea the further development of the wall of the ovary as the 

 pericarp has to be especially considered. The outermost, middle, and 

 innermost layers of this are distinguished as EXOCARP, MESOCARP, and 

 ENDOCARP respectively. According to the nature of the pericarp the 

 forms of fruit may be classified as follows : — 



1. A fruit with a dry pericarp, which opens Avhen ripe, is termed 

 a CAPSULE (Fig. 486). When dehiscence takes place by a separation 

 of the carpels along their lines of union the capsule is SEPTICIDAL; 

 when the separate loculi open by means of a longitudinal split, it is 

 termed loculicidal, and when definite circumscribed openings are 

 formed, it is termed PORICIDAL. As special types of frequent 

 occurrence may be mentioned : The follicle, which is a capsule 

 developed from a single carpel and opening by separation of the 

 ventral suture, e.g. Aconitum napellus (Fig. 563) : The legume or 



fl 



