72 



110*4*7 



[Ch. XII 



288. Liliaceous, a coiolla with six petals, spreading 



from the ba^se, so as to exhibit a bell-form appearance, as in 1,1* 

 Tulip and Lily. 



289. Rosaceous, & corolla formed of roundish spreading petals* 

 without elaws, or with very short ones, as the Rose and" Apple. 



. 50. 5><JO. Papilionaceous, a ttuvvur 



with a banner, two wings, and a 

 keel ; the name is derived from t he- 

 word papilio, a butterfly, on ac- 

 count of a supposed resemblance 

 to this insect, as in the Pea bios 



\sorn, (Fig. 50.) 



' 291. When a corolla is of no 

 determinate form, it is said to bf 

 anomalous. 



Odour of Flowers. 



292. The odour of flowers has its origin in the volatile oils, 

 elaborated by the corolla. 



293. Temperature renders the odours of flowers more or less 

 sensible; if the heat is powerful, it dissipates the volatile oils 

 more rapidly than they are renewed ; if the heat is very feeble, 

 :he volatile oils remain concentrated in the little cells where 

 Jiey were elaborated ; in both cases the flowers appear to have 

 but little odour. But if the heat is neither too great nor too little 

 the volatile oils exhale without being dissipated, forming a per 

 fumed atmosphere around the flowers. 



294. You see now the reason, that when you walk in a g*r 

 den in the morning, or towards evening, the iiowers seem mor* 

 fragrant than in the middle of the day. The air being also more 

 damp causes an increase of fragrance at those limes, as thfl 

 moisture, by penetrating the delicate tissue of she corollas, ex* 

 pel* the volatile oils. 



SSH. What is a liliaceous corolla 1 



2K 1 . What is a rosaceous corolla! 



200. What is a papilionaceous corolla 7 



2i)l. When is a corolla said to be anomalous 1 



292. What causes the odour of flowers 7 



293. What effect has temperature upon the odour of flowers 1 



294. Why do flowers appear peculiarly fragrant in the rooming 

 nd eveubg ? 





