ODOURS OF FLOWERS. 



329 



684. Kb'hler and Schubler have endeavoured to determine the 

 relative proportions between the different colours met with in flowers. 

 They examined upwards of 4000 species, belonging to twenty-seven 

 natural orders, of which twenty were dicotyledonous, and seven mono- 

 cotyledonous. The following are some of their conclusions : 



1. White 1193 



2. Yellow 951 



3. Red 923 



4. Blue 594 



5. Violet... .. 307 



6. Green 153 



7. Orange 50 



8. Brown 18 



9. Nearly Black 8 



685. The proportion of white, cyanic, and xanthic flowers varies in 

 different quarters of the globe, and at different elevations. The fol- 

 lowing are the proportions of colour in different natural orders, deduced 

 from the examination of about 120 species of each: 



Ked. Violet. Blue. Green. Yel. Orange. White. 



Nymphaeacea; 11 14 



Rosacese 52 1 



PrimulaceiE 41 7 6 2 



Boraginaceaj 10 9 28 3 



Convolvulacese 39 10 12 



Ranunculacese 16 4 15 2 



Papaveracese 38 9 



Campanulaceas 5 21 58 



28 

 52 

 15 

 13 



7 



42 

 36 



3 



10 

 1 

 2 

 1 



46 

 40 

 27 

 35 

 27 

 19 

 7 

 10 



Thus, Nymphasaceaj and Eosacea?, according to Schubler and Kohler's 

 observations, contain a large number of white flowering species; Primu- 

 lacese and Convolvulaceas, red; Companulaceaj, blue; Ranunculaceae, 

 yellow. 



686. In arranging flowers in a garden, it is of importance to place 

 the complementary colours together, in order to produce the best effect. 

 The complementary colour of red, or that which is required to make 

 white light, is green ; of orange, blue ; of yellow, violet ; consequently 

 blue and orange coloured flowers, yellow and violet, may be placed 

 together ; while red and rose-coloured flowers harmonize well with their 

 own green leaves. When the colours do not agree, the interposition 

 of white often restores harmony. 



5. ODOURS OF FLOWERS. 



687. The peculiar odours of plants depend on various secreted 

 volatile matters, which are often so subtle as to be incapable of detec- 

 tion by ordinary chemical means. Nothing is known of the causes 

 which render one flower odoriferous and another scentless. In some 

 cases the odours of plants remain after being dried, but in general they 

 disappear. Some leaves, as of the Woodruff, become scented only 



