406 Dr. Dickie on Associations of Colour and Relations 



When only one colour is present, it is usually more intense 

 in the odd lobe. 



When there are two colours, one of them is very generally 

 confined to the odd lobe. Sometimes when only one colour is 

 present and of uniform intensity in all the pieces, the odd lobe 

 has spots or streaks of white. This piece of the corolla therefore 

 in irregular flowers is distinguished from the others not merely 

 by size, form and position, but also by its colour. 



Papilionacese present examples of this law ; a few instances 

 may suffice. 



Cytisus Laburnum. 

 4 petals yellow. 

 5th yellow with purple veins. 



Lathyrus pratensis. 



Much the same as Laburnum. 



Trifolium pratense. 



Odd lobe distinguished from the others by its darker purple 

 veins. 



Kennedia monophylla. 

 4 petals purple. 

 5th yellow eye and purple margin. 



Swainsonia purpurea. 

 4 petals purple. 

 5th white eye on purple ground. 



Even when the odd lobe of a papilionaceous plant is smallest, 

 — not a common case, — it may be distinguished by its colour ; 

 for instance, in Brachysema acuminatum the odd lobe is compa- 

 ratively small, but has yellow eye and purple margin. 



Irregular gamopetalous corollse also present examples of this 

 law. 



Ajuga reptans. 



Corolla i 4 divisious P ur P le - 

 . \ 5th has yellow spot on inner surface. 



Thymus Serpyllum. 



Corolla, generally red-purple. 

 Two pale spots on odd lobe. 



Galeopsis Tetrahit. 



Odd lobe has generally two colours, yellow and purple. 



Numerous other examples from Labiatse might be quoted. 

 Among Scrophulariacese we may instance the following : — 



