324 THE FRUIT. 



suture of each component carpel opening directly into the back of 

 the cells, when the pericarp is more than one-celled ; whence this 

 dehiscence is said to be loculicidal (as in Fig. 621, 908, 919, and 

 the diagram, Fig. 436). In such cases the dissepiments remain 

 attached to the middle of, each valve. In the Helianthemum 

 (Fig. 549), and many other plants, we have an example of locu- 

 licidal dehiscence in a one- celled pericarp with parietal placentae ; 

 which in this case are borne directly on the middle of each valve. 

 On the other hand, septicidal dehiscence in a similar pericarp is 

 at once recognizable by the placenta occupying the margins of 

 the valves. 



597. Sometimes the placentse, being firmly coherent with each 

 other, break away from the dissepiments and remain united in the 

 axis, forming a column, or columella, as in Rhododendron (Fig. 

 793), Polemonium, and Collomia (Fig. 908), &c. 



598. Occasionally the dissepiments remain coherent with the 

 axis while the valves separate from them, as in the Morning Glory 

 (Fig. 924), and in the diagram, Fig. 437. This modification is 

 termed septifragal dehiscence. In like manner, parietal placentae 

 occasionally separate from the valves, forming what has been 

 termed a replum ; as in Cruciferous plants, and in the Poppy Fam- 

 ily. The same name is applied to the persistent border of the 

 simple pod of Mimosa (Fig. 441). 



599. Instead of splitting into separate pieces, the sutures of the 

 pericarp sometimes open for a short distance at their apex only, as 

 in some Chickweeds, and in Tobacco (Fig. 936), and the Primrose 

 (Fig. 826) ; or by mere points or pores, as in the Poppy. 



600. In a few cases the opening takes place by a transverse 

 line passing round the pericarp across the sutures, so that the up- 

 per part falls off like a lid; as in Anagallis (Fig. 830), the Plan- 

 tain (Fig. 833), the Henbane (941), and the Purslane (Fig. 568). 

 In Jeffersonia, the opening extends only half way round the peri- 

 carp, and the lid remains attached by the other side, as by a hinge. 

 This anomalous dehiscence is termed circumcissile or transverse. 



SECT. II. THE KINDS OF FRUIT. 



601. The various kinds of fruits have been minutely classified 

 and named ; but the terms in ordinary use are not very numerous. 

 A rigorously exact and particular classification, discriminating be- 



