STRUCTURE OF FLOWERS. 55 



which spring from the top of the claw, and spread out 

 into the limb, are in general less distinct, thick, and 

 regular, than the nerves of leaves ; the same terms of 

 Penninerved, Palminerved, &c. may be applied to 

 them, but there is seldom any necessity for describing 

 them. The corollas of the Composite present a dispo- 

 sition of the nerves which is peculiar to them ; viz. each 

 petal, instead of having as usual a middle nerve, is fur- 

 nished with a very perceptible one upon its two margins, 

 as far as the apex ; whence it results, that in the tube of 

 the corolla, where the petals are united, we see five large 

 nerves, each of which proceeds from one of the sinuses, 

 and is formed by the union of the two marginal ones. 



When the petals are free and furnished with claws, as 

 in the Pink, these claws are usually straight and near 

 together, thus forming a kind of tube with five slits. If, 

 on the contrary, they are united, as in the Tobacco, 

 their union forms a true entire Tube ; and the limbs of 

 these petals united by their claws, may be either entirely 

 free, or united half-way, or as far as the apex. 



The entrance of the tube bears the name of the 

 Throat (faux) : we may here frequently remark little 

 petaloid appendages, which have received the name of 

 Scales or Appendages when they are free, and which 

 are called the Crown when they are united together, or 

 when it is wished to designate them collectively. 



The use of the corolla is evidently to serve for the 

 protection of the sexual organs, especially before their 

 complete developement. Its fugacity, and its nature, so 

 distant from a foliaceous one, do not permit us to assign 

 it any use with regard to the nutrition. 



