152 
H. F. Wernham. 
These suggested evolutionary lines, together with the others 
with which we shall deal in the present chapter, are indicated 
in the accompanying diagram. 
Two further lines of descent from the scrophulariaceous off¬ 
shoot of the Multiovulatae-stock remain to be considered ; first, the 
line leading to Gesneraceae, and thence, possibly, to Columelli- 
aceae; and second, the line terminated by Acanthaceae. 
Diagram illustrating the possible affinities of the Higher Tubiflone. 
The Gesneraceae are, with the rarest exceptions, herbaceous 
or suffruticose in habit. Considered from the point of view 
of advance upon the scrophulariaceous stock, the only material 
feature seems to be the enlargement or conspicuous colouring (often 
