16 HEDWIG ON THE ORGANS df 



may be seen in the figures ; for it is evident thai 

 the areas in the seed lobes of Perilla ocymdides, 

 (PL I. Fig. i.) are more numerous and larger 

 than those in the stock gilly-floWer, Cheiranthui 

 incanus (Fig; 2.), arid the calyx of the red lily 

 (Fig. 4.) contains fewer of them than the leaves 

 of its stalk. (Fig. 3.) 



Though the observations here given on the 

 ducts and apertures in the cuticle of different 

 parts of plants are but few, yet they seem clearly to 

 prove that these organs are calculated for the pur- 

 pose of vegetable perspiration. The circumstance 

 that the apertures alluded to are always found 

 abundantly on trie lower surface of the leaves, 

 and indeed in many plants exclusively so, seeiris 

 to throw some light on several phcenomena ; 

 as for instance, why the leaves with their upper 

 surface turned downward, always regain their 

 former direction ; why those leaves which Bonnet 

 covered with oil, soon turned black,— and why a 

 shower of rain, or an imitation of it, is so very- 

 beneficial to plants. With respect to the last men- 

 tioned circumstance^ it seems probable to me, tha* 



