Wall-Rue 29 
in the following case, and vice versa. The leaflets remaining are 
thus rendered alternate on the rachis. 
Almost coincidently with the formation of this primary rachis, 
similar development of leaflets upon it into secondary leaflet- 
bearing rachises is begun (Figs. 5 e, 6e,and 7eg). This is some- 
times followed by similar development of leaflets upon the sec- 
ondary rachises into tertiary leaflet-bearing rachises (Figs. 9 h, 
10h’). 
It will be noted that in each instance development of the leaf- 
lets of each rachis into leaflet-bearing rachises begins with the 
leaflet lowest (first formed) on that rachis, and involves succes- 
sively the leaflets above in the order in which they were formed; 
and that likewise the formation of the tertiary rachises begins on 
the lowest (first formed) secondary rachises, and involves suc- 
cessively the secondary rachises above in the order in which they 
were formed. 
The venation is flabellate. In consequence,* each incision 
that transforms a leaflet or simple leaf-blade into two leaflets 
occurs between the vein-branches formed by the first forking of 
the vein that enters that leaflet or leaf-blade. Each branch thus 
becomes the vein entering one of the new leaflets; and the first 
forking of the one entering the leaflet that is in turn to subdivide 
forms the two branches between which the incision is to occur, 
while the part of it below its first fork is contained in that leaf- 
let’s base, which finally becomes elongate and forms a section of 
rachis. Sometimes the subdivision of a new leaflet takes place 
before it becomes fully separated from the old one, giving the old 
the appearance of being cut into three. 
When a leaflet on one rachis subdivides in the beginning of 
* See Chapter I, pp. 19 and 20. 
