360 
PHYSIOLOGY. 
BOOK II. 
Red 
Orange red 
Orange 
Orange-yellow 
Yellow 
Yellow-green 
Oxydized or 
Xanthic series. 
Green 
Greenish-blue 
Blue 
Violet-blue 
Violet 
Violet-red 
Red 
Colour of leaves. 
Disoxydized or 
Cyanic series. 
" Which may be otherwise expressed thus — 
Green. 
O ^3 . 
a >2 Q) 
O w 
' Greenish-blue 
Blue 
Violet-blue 
Violet 
Violet-red 
Yellow-green 
Yellow 
Orange-yellow. 
Orange 
Orange -red 
Red. 
o 
" It will be at once remarked, in considering these tables, 
that almost all flowers susceptible of changing colour only do 
it in general by rising or descending in the series to which 
they belong. Thus in the xanthic series, the flowers of Mar- 
vel of Peru may be yellow, orange-yellow, or red ; those of 
the Austrian rose, orange-yellow or orange-red ; those of the 
Nasturtium vary from yellow to orange and orange-red ; those 
of the garden Ranunculus pass through every gradation in the 
series, from red to green. As to the cyanic series, the Ane- 
mone varies from blue to violet and red ; the Hyacinth from 
green to red through all the gradations ; the Lithospermum 
purpuro-coeruleum from blue to violet-red; and the China 
aster from violet-bhie to violet, violet-red, and red. 
" Although there are certain exceptions to these rules, par- 
ticularly in the Hyacinths, some of whose varieties approach 
the xanthic series, yet they are so far conformable to nature 
as to help us either in searching for the causes of colours, or 
in predicting the possible varieties of colour in flowers of the 
same species, and sometimes of the same genus. 
" To the xanthic series belong all, or nearly all, the species 
of Cactus, Fig- Marigold, Aloe, Cytisus, Wood sorrel. Rose, 
Mullein, Potentilla, CEnothera, Ranunculus, Adonis, Tulip, 
&c. ; to the cyanic series those of Campanula, Phlox, Epilo- 
bium. Hyacinth, Geranium, Anagallis, Globularia, &c. 
Hence we may assume that there is in general a relation be- 
tween the colours of flowers and generic classification — an 
hypothesis which may be the more readily admitted when it is 
