150 BOTANY. 



PUNCTUATED VESSELS. 



Cylindrical vessels, spotted with opaque points or dots, dis- 

 posed in series, sometimes parallel, sometimes slightly oblique, 

 and marked with paler rays, like rings, or in spirals, distant 

 from each other by the diameter of the tube, at least. Diameter 

 generally greater than the tracheae. 



MONILIFORM VESSELS. 



Tubes punctuated, ramified, and slightly curved at irregu- 

 lar intervals; they are frequent in roots, articulations, or at 

 the origin of branches and leaves. 



RETICULAR VESSELS. 



Cylindrical tubes, whose surface is covered with transversal, 

 oblong spots, giving it the appearance of a net. Kieser has 

 observed them in the Balsam and Nasturtium, principally in 

 the root; he regards them as a modification of tracheae, in 

 which the spires are unequally combined. Lindley has found 

 them in the Papyrus and Lily ; Parkinge in the tissue which 

 forms the internal portion of the cells of the anthers. 



COMPOSITE ORGANS. INTERNAL ARRANGEMENT. 



FIBRES. 



Collections of vessels, composed generally, and especially 

 in the wood, of punctuated vessels and tracheae, surrounded 

 by elongated, fusiform cells; the most solid fibres known are 

 those of the Phormium Tenax, vulgarly called New Zealand 

 Flax, which will support a weight represented by sixteen and 

 one-third, those of flax supporting a weight represented by 

 eleven and one-third. 



RESERVOIRS OF THE PROPER JUICES. 



Regular cavities produced in the tissue of vegetables by 

 juices of diverse natures, generally coloured and odorous, 

 which distend the cells and break their walls. These cavities 

 are also improperly called vessels. 



AERIAL CAVITIES. 



Empty spaces of the size of three or four cells, produced 

 either by a too rapid enlargement, or by a natural disposition 



