these traces represent only the lateral stamens of the 
outer whorl and that these cannot be considered to be 
otherwise is proved by the fact that they originate after 
the stigmatic traces have been separated off and before 
the trifurcation which results in the formation of the me- 
dian and marginal traces of the respective perianth mem- 
ber. In EH. epidendraea (Fig. 7 C and D), the main 
traces, LP, underlying the lateral petals, before splitting 
up to form the supply to the corresponding perianth 
members, give out the traces al and a2 which obviously 
represent the traces for the lateral stamens of the inner 
whorl. That these traces cannot be interpreted otherwise 
is borne out by the point of their separation from the 
main trace, LP. 
B. In other orchids, the degree of expression of the 
traces for the stamens of the two whorls is complicated 
by the associated phenomenon of adnation. The series 
of diagrammatic illustrations in Fig. 8 is intended to 
convey the increasing complexity in the origin of the 
staminal traces. In these figures the behavior of one pair 
of the main traces (LP and LS) underlying the lateral 
perianth members of one side of the flower is shown. A 
illustrates the simplest condition where there is no fusion ; 
the staminal traces a2 (belonging to the inner whorl) and 
A8 (belonging to the outer whorl) are quite distinct both 
in origin and further course. In B, the two traces are 
still distinct; but their separation from the respective 
main traces is postponed until after the trifurcation of the 
main traces themselves; thus the position of the origin 
of the staminal traces is carried up to a higher level in 
relation to the floral axis. In C, the position of origin of 
the two staminal traces is carried up still higher; they 
originate at a point nearer to the anastomosing point of 
the marginal traces. Furthermore, the two staminal 
[ 79 | 
