276 OF THE SEED VESSEL AND ITS KINDS. 



Geum rivale, Engl, Bot. t. 106, when 

 cultivated in dry gravelly ground, exhibits 

 such transformations in abundance. Be- 

 tween petals and stamens there is evidently 

 more connection, as to their nature and 

 functions, than between any other organs, 

 and they commonly flourish and fall to- 

 gether. Yet only one instance is known 

 of petals changing to stamens, which Dr. 

 Withering has commemorated, in the 

 Black Currant, Ribes nigrum. On the 

 other hand, nothing is more frequent than 

 the alteration of stamens to petals. Here 

 then the metamorphosis begins to be re- 

 trograde, and it is still more so in the 

 Cherry above mentioned, by which we re- 

 turn to the herbage again. — The line of 

 distinction seems to be most absolute be- 

 tween stamens and pistils, which never 

 change into each other ; on the contrary, 

 pistils, as we see, rather turn into petals, 

 or even into leaves. 



5w Pericarpium. The seed-vessel, ex- 

 tremely various in different plants, is 

 formed of the germen enlarged, It is not 



