ITS KINDS. 291 



either extending part waj r round, as in the pod of JcfTcrsonia, 

 or completely round, so that the upper part falls off like an 

 unhinged lid. This circumscissile dehiscence occurs in many 

 plants of widely different orders ; such, for example, as Purslane 

 (Fig. 621), genuine Amaranths, Plantain, Pimpernel, and Hen- 

 bane. In other cases, as in Antirrhinum (Snap-dragon) and 

 its allies, the cells burst by irregular laceration at a definite 

 point, and discharge the seeds through the ragged perforation ; 

 or one or more neat valvular orifices are formed on some parts 

 of the wall, as in Campanula. 



SECTION II. THE KINDS OF FRUIT. 



554. FRUITS have been minutely classified and named; 1 but 

 the terms in ordinary use are not very numerous. A rigorously 

 exact and particular classification, discriminating between the 

 fruits derived from simple and from compound pistils, or between 

 those with and without an adnate calyx, is too recondite and 

 technical, and sometimes too hypothetical, for practical pur- 

 poses. It is neither convenient nor philosophical to give a 

 substantive name to every modification of the same organ. For 

 all ordinary purposes, both of morphological and systematic 

 botany, it will suffice to characterize the principal kinds under 

 the four classes of 



Simple fruits, those which result from the ripening of a single 

 pistil ; 



Aggregate, those of a cluster of carpels of one flower crowded 

 into a mass ; 



Accessory or Anthocarpus, where the principal mass consists 

 of the surroundings or support of either a simple or an aggregate 

 fruit ; 



Multiple or Collective, formed by the union or compact aggre- 

 gation of the pistils of several flowers, or of more than one. 



555. Simple Fruits may be distinguished, upon differences of 

 texture, into Dry Fruits, Stone Fruits, and Baccate Fruits ; or, 

 better, into Dry and Fleshy ; and the first may be divided into 



1 The greater part of the forty-three substantive names of Desvaux's, 

 and even of the thirty-six of Dumortier's and of Lindley's elaborate classi- 

 fications of fruits have never found employment in systematic botany, and 

 doubtless never will be used. Yet a detailed carpological classification has 

 its uses for the student. Among the more recent attempts are the successive 

 ones of Dickson, McNab, and Masters. See Nature, iv. 347 (also in Trimen's 

 Jour. Bot. 1871, 310), iv. 475, and v. 6. 



