considered in Relation to the Phyllode Theory. 453 
clear case of phyllody, Sowerbeia juncea,-Sm ., is a typical example. As the 
accompanying diagrams (Figs. 14 A-C, p.454) show, three separate vascular 
strands traverse the leaf-sheath, but in the limb of the leaf, which is more or 
less triangular in section, there is a ring of bundles embedded in fibres. 
The structure essentially recalls that of one of the simpler leaves of Aspho - 
delus liburnicUs\ in which the inverted adaxial bundle has not branched), but 
differs from it in the aggregation of the bundles within a common sheath. 
Fig. 14 B may also be compared with the transverse section of certain 
Dicotyledonous petioles such as that of Clematis Vitalba 1 (Fig. 14 d). 
Sowerbeia laxiflora , Lindl., as Schulze 2 has pointed out, differs from 
the other members of the genus in retaining three distinct bundles in the 
limb. He speaks of the lateral bundles as being directed in an unusual 
sense, with the xylem pointing outwards. 3 My sections, however, show an 
orientation which is the reverse of that which he describes — the xylem of 
the laterals being directed towards the midrib (Fig. 1 5). This placing of 
the lateral bundles corresponds to that in the sheath of Arnocrinum 
Drummondii (Fig. 16 a). Besides the three main bundles to which he 
refers, I have found, in the limb, several very small additional bundles 
(b. in Fig. 15) ; I have seen as many as six of these in one .transverse 
section. I have not been able to trace their origin in detail, but their 
position suggests that they arise as branches of the main bundles. They 
correspond to the small bundles of Arnocrinam and Laxmannia (£ 2 , # 3 , b 4 , 
in Figs. 20 and 21). 
In Laxmannia grandifior a , Lindl., three bundles again enter the leaf- 
sheath (Fig. 19 A), which is continued upwards into a distinct free ligule 
( tig . in Fig. 19 B). In the limb, in which the bundles are aggregated into 
an axial strand, the development of fibres reaches a most unusual pitch. 
The stele of the leaf is shown in Fig. 19 C and on a larger scale in Fig. 21 ; 
it will be recognized that, in the case of the principal bundle, alt the 
elements — with the exception of the somewhat attenuated V of xylem, and 
a tiny patch of thin-walled cells on the inner side of the apex of each arm of 
the V — have become strongly thickened. The treatment necessary in 
preparing herbarium material for sectioning may possibly have exaggerated 
the width of the walls, but that the elements in question were, in fact, thick- 
walled fibres admits of no doubt. 
In the genera Alania and Borya , the vascular system is so much 
reduced that it appears, in the limb, as Schulze points out, to consist of 
a single bundle only. 
Schulze mentions that he was unable to obtain material of the leaves 
of Arnocrinum , so I have studied the structural plan of A. Drummondii , 
Endl., as fully as I could from the two or three more or less complete 
1 Petit, L. (1887), figures the petiole of this species. 
2 Schulze, R. (1893). ' 3 Ibid,, p. 334 . 
