432 
PHYSIOLOGY. 
BOOK II. 
at Tubingen, in 1825, by Messrs. Schlibler and Funk, is 
deserving of attention. From their account it appears that 
flowers may be divided into two great series : those having 
yellow for their type, and which are capable of passing into 
red or white, but never into blue ; and those of which blue is 
the type, which can pass into red or white, but never yellow. 
The first of these series is called by these observers oxidised, 
and the second disoxidised ; and they consider greenness as a 
state of equilibrium between the two series. De Candolle 
calls the first series xanthic, and the last cyanic. Upon this 
principle they admit the following scale, leaving white out of 
consideration : — 
Red 
Orange-red 
Orange 
Orange-yellow [ 
Yellow 
Yellow-green J 
Xanthic series 
Red 
Violet-red 
Violet 
Violet-blue 
Blue 
Greenish-blue 
Green, Colour of leaves. 
Which may be otherwise expressed thus : 
Green. 
Cyanic series. 
' Greenish-blue 
Yellow* green '| 
Blue 
Yellow 
- Violet-blue 
Orange-yellow > 
Violet 
Orange 
Violet-red 
Orange-red J 
Cyanic series. 
Xanthic series. 
Red. 
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 
purpureo-caeruleum from blue to violet-red ; and the China 
Aster from violet-blue to violet, violet-red, and red. 
Although there are certain exceptions to these rules, par- 
ticularly in the Hyacinths, some of whose varieties approach 
