16 On the Colour and Smell of Plants. 



c Yellow flowering genera, containing 70 100 percent, white in their flowers. 



In 73 species there are 18 odoriferous, and hence 24.65 per cent. 

 6. Orange-Red flowering Genera. 



The two genera with 6 per cent, white, contain no odori- 

 ferous species ; the genus containing 33 per cent, white, con- 

 tains 3 odoriferous species ; hence in the 3 genera of this co- 

 lour there are 10.71 per cent, odoriferous species. 



If we collect the chief results of this arrangement in a gene- 

 ral view, we obtain the following relations between colour and 

 smell : 



The increase of odoriferous species in proportion to the di- 

 minution of colouring matter is evident in each of these prin- 

 cipal colours, as has been already remarked above. This seems 

 also to be the case in the orange-red colour, but before such a 

 circumstance can be ascertained with certainty, new investiga- 

 tions must be made. 



It would, however, hardly have been safe to extend to the 

 whole vegetable kingdom the interesting laws determined and as- 

 certained regarding the 4200 species whose colour and smell were 

 examined. New and extensive investigations were still indis- 



