OF THE SEED-VESSEL AND ITS KINDS. 211 



tioned, by Avhich we return to the lierbage again.- — 

 The line of distinction seems tx) be most absolute 

 between stamens and pistils, which never change 

 into each other ; on the contary, pistils, as we see, 

 rather turn into petals, or even into leaves. 



Pericarpium. The seed-vessel, extremely various 

 in ditferent plants, is formed of the germen enlarged. 

 It is not an essential part, the seeds being frequently 

 naked, and guarded only by the calyx, as in the 

 first order of the Linnasan class Didynamiay of 

 which Lamiuviy EugL Bot. t. 768, and Galeopsisy 

 t, 667 y are examples; also in the great class of 

 compound flowers, Sy7igenesia, as well as in Rumex, 

 t. 724, Polygommiy t. 989, the Umbelliferous tribe, 

 numerous Grasses, &c. 



The use of the Seed-vessel is to protect the seeds 

 till ripe, and then in some way or other to promote 

 their dispersion, either scattering them by its elastic 

 po^ver, or serving for the food of animals in whose 

 dung the seeds vegetate, or promoting the same 

 end by various other means. The same organ which 

 remains closed so long as it is juicy or moist, splits 

 and flies asunder when dry, thus scattering the seeds 

 in weather most favourable for their success. By an 

 extraordinary provision of Nature, however, in some 

 annual speciesof Mesembri/anthemumyf. 178, natives 

 of sandy desertsin Africa, the seed-vessel opens only 

 in rainy weather ; otherwise the seeds might, in that 



P2 



