226 T etracyclidece . 
“ apetaly.” Examples of flowers with but a single whorl of perianth 
are afforded by the ashes ( Fraximis ), and by the genera Forestiera 
and Olea ; these examples seem to possess no little importance as 
suggesting the possibility that many of the “ Apetalse ” may have 
originated similarly by degradation from sympetalous ancestors. 
In view of the foregoing considerations, we are led to regard 
the Jasminales {supra) as representing a terminal point on a line of 
descent separate from that of the apocynal stock which branched 
off from the latter line somewhat as indicated in the diagram on 
p. 222. The apocynal stock and its immediate derivatives, we shall 
see on the other hand, do not appear in any sense to represent a 
terminal evolutionary point, for we shall find many reasons in favour 
af connecting them by a series of transitional forms with the 
important group Tubiflorae, which now presents itself for our 
consideration. 
{to be continued). 
