CONNECTION OF THE BUNDLE-SYSTEMS. 3II 



b. Monocotyledons and Phanerogams with axile bundle. 



Sect. 95. Among the Monocotyledons belonging to the Palm-type (Sect. 65-67) the 

 numerous bundles of the lowest internode of the normal axillary shoot enter, in the 

 PalmsS Dracaenas, Liliacese, Aroideoe, Orchidaceae, &c., at the node into the bundle- 

 cylinder of the main shoot, and pass obliquely downwards and inwards with the 

 bundles of the leaf which bears the shoot, inserting themselves successively on peri- 

 pheral bundles of the latter, without reaching the middle of the cylinder. In many 

 cases, as in the rhizomes of Acorus, the axillary bundles do not penetrate further 

 than to the surface of the cylinder of the main shoot, but spread themselves out, with 

 abundant branching, for a great distance downwards, over the nearer longitudinal 

 half of the main shoot, and Interweaving, and here and there uniting with the bundles 

 at the surface of the cyhnder, they form a dense plexus of bundles, which is sharply 

 limited on the side next the cortex. 



In those forms which have been investigated, Zea, Saccharum, Coix, Arundo 

 Donax, &c., numerous bundles pass from the lowest internode of the axiUary shoot 

 transversely into the node, and here branch very freely, their branches spreading over 

 the whole transverse section of the node, but only slightly in a vertical direction, and 

 thrusting themselves between the bundles of the main axis, which run perpendicularly 

 through the node, and between one another, and here and there inserting themselves 

 on the bundles of the main axis. The whole series of axillary bundles forms at the 

 node a complex and confused felt, expanded and attached in the manner indicated, 

 and having the form of a transverse disc, which in the above-named large species 

 reaches a height of several millimetres '■' ; its origin is not obvious in the mature state, 

 but it is clearly seen in young stages of development that it is formed by the insertion 

 of bundles, starting from the axillary shoot. 



In the Commelinese with thin stems, as TradescaiitiS'- albiflora, Commelina 

 agraria, several internal bundles are found in the basal internode of the young 

 axillary shoot (comp. Sect. 69) — e. g. three or four in the Tradescantia named — which 

 enter the node of the main shoot, and here, turning downwards above the outgoing 

 median bundle of the leaf which bears the shoot, insert themselves at the point of 

 union of the inner bundles. In somewhat older axiUary shoots there are further 

 peripheral, doubtless in part cauline bundles, which insert themselves on the cauline 

 bundles of the main shoot. In thick-stemmed Commelinese, such as Maravelia zey- 

 lanica and species of Dichorisandra, the internal bundles of the lowest internode of the 

 axillary shoot unite to a single thick bundle, which passes almost exactly horizontally 

 into the node of the leaf which bears it, and inserts itself in the middle of this, with 

 some few branches, on the internal bundles which descend there. In Tradescantia 

 virginiana several bundles pass from the axillary shoot into the node of the leaf 

 which bears it, and there divide into branches, which are interwoven as in the nodes 

 of the Grasses between the internal bundles of the main shoot, and insert themselves 

 on them. 



• Mohl, Palm. Struct, p. 31. — Compare also Falkenberg, I.e., and the note above on p. 276. 

 ^ Compare von Mohl, /. c. Tab. 9 ; Schleiden, Grundz. 3 Aufl. II. p. 1 58. 



