114 



8TRUCTUKAL BOTANY. 



do the petals of Magnolia ; and lastly, the Vexillary, when one 

 piece larger than the rest is folded over them, as in Pea (425). 



340. Plicate or folded aestivation occurs in tubular or mono- 

 petalous flowers, and has many varieties, of which the most re- 

 markable is the supervolute, where the projecting folds all turn 

 obliquely in the same direction, as in the Morning-glory, Thorn- 

 apple (Datura). 



420 



Oiarjrajntof'Jlnwtrt (a* tern fn/ crons-fertionf'j. 126, Jeffersonia diphvlla , ovary; *, stamens; d, innei 

 row ol petals, aestivation triquetrous; b, outer row of petals, .estivation contorted; c, sepals, aestivation 

 luincuncial. 427, Lily. 428, Strawberry. 429, Mustard. The pupil will designate modes of sestivatiou. 



It will be seen by the cuts that different modes of aestivation 

 may occur in the different whorls of the same flower. 



Review. 330. What is the meaning of Metamorphosis ? IB the Flower a new principle ? 

 Whence is it? 331. Two sources of proof. 332. What is said of the Poppy? 333. State 

 the first argument. What is proved by this? Prove that the petals are leaves. Argu- 

 ment from the Water-lily From the Tulip-tree. 334. Define Teratology. State once 

 more the point to be proved. What are monstrous flowers ? How does the Rose become 

 double ? Change in the Double Cherry ? In Buttercups ? In fig. 417 ? 335. Meaning ol 

 ^Estivation ? Why is the subject important ? Meaning of Vernation ? How to observe 

 them ? 336. Four general modes of ^Estivation. 337. Define the Valvate Its two va- 

 rieties. 338. Define the Contorted. 339. Define the Imbricated The Quincuncial Tri- 

 quetrous Convolute. How is it in the Pea? Describe the aestivation of Convolvulus 



CHAPTER XXV. 



INFLORESCENCE. 



341. Inflorescence is a term denoting the arrangement of the 

 flowers and their position upon the plant. 



All the buds of a plant are supposed to be originally of one and the same nature, look- 

 ing to the production of vegetative organs only. But at a certain period, a portion of the 

 buds of the living plant, by an unerring instinct little understood, are converted from 

 their ordinary intention into flower-buds, as stated and illustrated in the foregoing C'hap- 

 UT. The flower-bud is incapable of extension. While the leaf-bud may unfold leaf aftei 

 leaf, and node after node, to an indefinite extent, the flower-bud blooms, dies, and arrest* 

 forever the extension of the axis which bore it. 



342. In position and arrangement, flower-buds cannot differ 

 from leaf-buds, and both are settled by the same unerring law 



