Manchester Meiiioirs, Vol. xlvi. (1902), No. 9- 13 



rootlet with the fossil described above, XeyiopJiyton 

 radicuhs7ivi, and consequently also with LepidopJiloios 

 fuliginosus. 



Another interesting feature of the present rootlet is 

 the fact that this middle cortex possessed meristematic 

 properties in its outer layers, as can be seen in Figs, i and 

 4 of Plate XIII. At all events, there are regions in which 

 distinct growth of a secondary nature has taken place. 

 This secondary tissue, which is not continuous around the 

 root, seems to have been formed in a centrifugal manner. 

 Its function must remain problematical, but was possibly 

 of a protective character and this tissue may have been 

 formed to replace the somewhat defective outer cortex 

 (see Plate XIII., Fig. i). I have also found similar patches 

 of secondary growth in the outermost layers of the middle 

 cortex in certain sections of the stem of Lepidophloios 

 fuliginosus. 



The inner cortex seems to have been of a more deli- 

 cate character than the middle cortex, but, unfortunately, 

 the central portion of the rootlet is cut somewhat obliquely, 

 so that its tissues are not very distinct in an enlarged view. 

 It will, however, be seen {Plate XIII., Fig. 3) that the inner 

 cortex consisted of four or five rows of cells, set more or 

 less closely together, very different in texture and 

 arrangement from the cells of the middle cortex. 



The stele shows the usual monarch arrangement of 

 the conducting tissues, if we take the space on one side of 

 the xylem to represent the position of the phloem elements. 

 The xylem has one very distinct group of smaller elements 

 which can be identified as protoxylem, though, as in many 

 stigmarian rootlets, a few small tracheids are found at the 

 opposite side of the xylem. 



The protoxylem elements will be seen to project 

 somewhat into the sheath formed by the inner cortex, as 



