20 
Plowman . — The Comparative Anatomy and 
of the next higher internode. The diagrams of Fig. 2 and the photographic 
Figs. 1 3 j will serve to make this point quite clear. And in the light 
of these facts the diagram G, Fig. 1 , will convey a more or less correct 
idea of the course of the bundles in the stem of Scirpus cyperinus , which 
is in this respect typical of the greater part of the Cyperaceae. 
It appears evident, then, that the bundles of the leaf-trace in most 
Cyperaceae do not enter the cauline system of the stem at the point 
of insertion of the leaf, either in the manner described by Mohl (33), 
De Bary (12), and Kny (32), for the Palms, or in that found by Falkenberg 
(16), Queva (39), and Chrysler (9), among the Liliales. The arrangement 
more nearly resembles that observed by Guillaud (19) in the cortical 
bundles of the rhizome of Acorus calamus (D, Fig. 1 ), with this important 
difference — that in the Cyperaceae all of the bundles of the leaf-trace pass 
down through one internode as cortical bundles. Consequently we find 
in the bundle arrangement of the aerial stem of most Cyperaceae nothing 
in common with Mohfs Palm type ; and the ‘ reparatory bundles ’ described 
by Queva (38), as occurring in Gloriosa , and observed by the writer 
in a confirmatory study of Streptopus , are here to be found, if at all, 
in the peripheral cauline bundles rather than in the medullary ones. 
Cortical bundles are of quite general occurrence in many widely 
separated groups of plants. Wossidlo (62) has described a dense anasto- 
mosing cortical system in the Cocos type of Palm. Wittmack (59) showed 
that the cortical strands in Musa ensete are connected by re-entrant 
anastomoses at the nodes with the cauline system, and De Bary (12) 
describes a similar re-entrant connexion of the amphivasal bundles in 
the secondary thickening of Dracaena. Sanio (41) considered the so-called 
sieve-tube strands in the cortex of Elodea to be greatly reduced cortical 
fibro-vascular bundles. More recently Hartog (22) has found typical 
cortical bundles in the Lecythideae (Myrtales) and in the Barringtoneae, 
while Boodle and Worsdell (5) have found less typical cortical strands 
in Castiarina. Col (10) describes cortical bundles in several Dicotyle- 
donous plants, and gives an admirable summary of the literature upon 
the subject of bundle-distribution. 
De Bary (12) indicates four general modes of arrangement of cortical 
bundles, as follows : — Firstly, all bundles of the leaf-trace enter the cauline 
system at the same node, after passing as cortical bundles through one 
or more internodes below the insertion of the leaf. Here De Bary places 
Casuarina and Osmunda , with single leaf-trace bundles ; species of Begonia , 
Aspidium , Pteris , Cyathea , &c., with several leaf-trace bundles ; and 
Rhipsalidaceae, with peculiar winged stems. Evidently we may now 
add to these the majority of the Cyperaceae with jointed culms. Secondly, 
the central leaf-trace bundle enters the central cylinder directly, while 
the lateral bundles pass down through the cortex to the next node. 
