MOBPHOLOGY OF THE FEUIT AND SEED 259 



When a fruit resembles the orclmary capsule in every respect, 

 except that it is inferior, as in the species of Iris (fig. 562) and 

 Cainpanula [figs. 530 and 531), it has received the name of 

 Diplotegia. 



2. The Siliqua is a superior, spuriously two-celled, many- 

 seeded, long, narrowfruit, dehiscing by two valves separating from 

 below upwards, and leaving the seeds attached to two parietal 

 placentas, which are commonly connected together by a spurious 

 vertical dissepiment, esjilei a, replum (fig. 563). The placentas 

 are here opposite to the lobes of the stigma, instead of alternate 

 with them, as is usually the case. Examples of this fruit occur 

 in the Wallflower {fig. 563), Stock, Cabbage, and a large number 

 of other Cruciferas. 



The siliqua is sometimes constricted in the spaces between 

 the seeds, like the lomentum, in which case it is iudehiscent, 

 as in Baphanus saiivus ; it is then called a lomentaceous 

 siliqua. 



8. The Silicula. — This fruit resembles the siliqua in every 

 respect except as to its shape ; and in usually containing fewer 

 seeds. The siliqua may be described as long and narrow, 

 the silicula as broad and short. Examples occur in the Shep- 

 herd's Purse (fig. 564) and Scurvy-grass. 



The silicula and siliqua are the characteristic forms of fruit 

 in the natural order Cruoiferse. 



4. The Diplotegia. — This is the only kind of inferior fruit 

 which presents a dry dehiscent pericarp. It has already been 

 stated under the head of Capsule, that the diplotegia differs 

 from the latter only in being inferior. The species of Iris 

 (fig. 562) and Oampanula (figs. 530 and 531) are examples of 

 this fruit. The diplotegia may open either by pores (fig. 530), 

 valves {fig. 562), or transversely, like the ordinary capsule. In 

 the latter case, as with the true capsule with transverse dehis- 

 cence, the fruit is called a Pyxis. 



5. The Cone. — As we have seen, the female flower of the 

 Coniferse has the form of an axis bearing a number of leaves 

 arranged spirally along it, each being regarded as an open carpel 

 with two ovules on its upper surface. When it becomes old 

 the carpels are hard and woody, and each bears two naked 

 seeds (fig. 475). Each cone is then a single fruit, as may be 

 seen in the Scotch Fir (fig. 565), the Larch, the Hemlock 

 Spruce (fig. 275), and a great many other plants of the same 

 natural order. The dehiscence is brought about by the carpel- 



S 2 



