Oct., I92I] BECHTEL — FLORAL ANATOMY OF URTICALES 403 
advance over other groups. Nor is the presence of zygomorphism, for 
example, an indication of relationship with another group in which the same 
feature is present. That the Urticales are related to one of those plexuses 
of the angiosperms possessing types of zygomorphism, namely: that cul- 
minating in the Monocotyledons, that of the Rosales in the Polypetalae, 
and that of the Tubiflorae in the Sympetalae, can receive no support. It 
does seem that a relationship more nearly correct may be discovered for the 
Urticales by considering the characters possessed by them that indicate 
primitiveness rather than those that indicate specialization, namely: many 
organs, non-cyclic conditions, and preponderance of woody forms. The one 
order of the angiosperms possessing these characters is the Ranales. The 
Ranales have not suffered reduction to any degree comparable with that 
of the Urticales. Floral anatomy of the members of the families of the 
Ranales may reveal important characters that macroscopic study cannot 
reach. However, the Urticales appear, when viewed from the standpoint 
of their primitive characters, to be parallel with the Ranales. The latter 
possesses a tendency to the pentamerous condition, and both orders possess 
a tendency to an unicarpellate condition. That the Urticales and Ranales 
are descendants from the same protoangiospermous plexus seems likely. 
But, since the flowers of the Urticales are greatly reduced in each set of 
organs, as the floral anatomy described above indicates, the Urticales are 
on a higher level than the Ranales. 
A feature of the Urticales that has caused them to be looked upon as 
very primitive plants among the angiosperms is the " orthotropous " ovule. 
This type of ovule has been regarded as the most primitive since it is 
apparently the common type appearing in those families classified as lowest 
in the Polypetalae. In the most highly reduced members of the Urticales, 
numbering about half the species of the order, the ovule is ''basal" or 
"orthotropous." Anatomical work reveals, however, that the ovule has 
become basal, as previously described, by a sinking or a sliding down from a 
pendulous position and that in this process the anatropous ovule has become 
erect. Thus the Urticaceae show a phyletic origin of the orthotropous ovule 
from an anatropous, pendulous, or lateral type, as Welsford and Benson 
(22) consider is the case in Juglans regia and related plants, basing their 
evidence also on anatomical study. The orthotropous ovule in this group, 
therefore, is not primitive. The floral anatomy of Bentham's Incompletae 
(15 orders), in which the ovule, with few exceptions, is basal, is an inviting 
line of research. In determining the phyletic relationship of the Urticales, 
therefore, it is the pendulous or lateral anatropous ovule that must be con- 
sidered and not the erect basal ovule. 
A consideration of the vascular supply to the ovule, as described in the 
species studied, may indicate that the Urticales are not a natural order. 
Three types of vascular supply to the ovule were found, but these are all 
the results of the greatly reduced condition of the flowers. The common 
