jo 6 Thomas. — Seedling Anatomy of 
manner. The plumule is noticeably late in differentiation. In seedlings 
which show plentiful metaxylem and crushed protoxylem, there is no sign 
of lignification in the plumular rudiments. 1 
Clematis recta possesses a short cotyledonary tube, and presents the 
usual type of anatomy. 
Clematis orientalis (Text-fig. n). The cotyledonary strands are double 
in the cotyledons of this form, as in C. flammula. The transition is quite 
normal ; the xylem of the root does not meet in the centre of the diarch 
plate but is present in two pegtop-shaped clumps, the broad ends of which 
are directed towards one another, but do not touch. 
Clematis glauc a and Clematis alpina call for no remark. 
Clematis Davidiana. An interesting 
peculiarity was met with in one individual 
of this species (Text-fig. 12), which showed 
a single cotyledonary member evidently 
produced by marginal fusion of the pair. 
The two vascular strands of this member 
approached each other at the node, and it 
would seem that the diarch plate is formed 
in the normal plane, i. e. that passing through 
the supposed centres of the cotyledons. 
Comparison with similar anomalies in Ane- 
mone sylvestris and A. pidsatilla adds 
interest to this occurrence. 
C. Header soni and C. viticella (Text- 
figs. 13 and 14). These species stand out 
from the others by virtue of the posses- 
sion of lateral strands in the base of the 
cotyledon. These strands pass into the hypocotyl independently of the 
double bundle and unite with the corresponding bundle from the other 
cotyledon. There may be said to be practically a tetrarch stage, inas- 
much as the small phloem groups of the laterals divide in the hypo- 
cotyl, so that the intercotyledonary protoxylem elements are exarch, although 
through their disappearance the root in its final form is diarch. The 
tetrarch appearance is enhanced in older seedlings by the production 
of four masses of secondary xylem, leaving rays in the intercotyledonary 
plane which are almost as marked as those in the cotyledonary plane. 
Thalictrum flavum , T. glaucum i T. javanicum , and T. adi antifolium. 
This genus presents many histological peculiarities which will not be 
considered in this paper. The transitional features of the four species 
examined are quite alike, and similar to those of the genera described above. 
1 The terms protoxylem and metaxylem are applied in a purely relative sense throughout this 
paper and no precise or histological meaning is to be attached to them. 
Text-figs. 10-14. 10, Clematis 
flammula ; 1 1 , C. orientalis ; 12, C. 
.Davidiana ; 13, C. Hendersoni\ 14, 
C. viticella. All reduced about 
