172 Transactions. 



The stele of the Antipodes Island form of L. varium., which is shown in 

 Plate IX, fig. 1, B, is illustrated in fig. 2. This is practically identical 

 in all particulars with that of the Macquarie Island plant, although in 

 fig. 2 it will be seen that the phloem and not the xylem radiates from 

 a common centre ; also, there is a close correspondence in the nature of 

 the three cortical zones. There is a decided tendency at the base of the 

 stem towards the formation of one or more plates of xylem and phloem 

 extending right across the stele, and lying parallel with each other. 

 I noticed in my sections that this was most marked at a point where the 

 stele was about to fork ; but this point needs further investigation. 



In fig. 3 is shown the stele of the Camj^bell Island form of L. varium. 

 It will be remembered that this plant is described by Hooker as the largest 

 form of L. varium^ seen by him. Probably in the full-grown stem the stele 

 will be even larger than shown in this figure, but it will be clear from a 

 comparison with figs. 1 and 2 that with the growth in size of the stele the 

 simple radial form becomes more complex through the connecting across 

 of some of the phloem bands or by the isolation of groups of phloem or of 

 xylem into islands. This is the particular form of L. varium whose stele 

 is figured in Part I of the present series of papers (16. fig. 87). The 

 proto])hloem is clearly to be distinguished, and there is a large amount 

 of phloem. The cells of the latter tissue are uniform in size, but those 

 which lie immediately adjacent to the xylem bands show abundant contents, 

 while those placed centrally in the phloem groups and bands are empty. 

 There is a very distinct pericycle two to three cells in width, the cells of 

 which show abundant contents. Thus along with the luxuriant growth 

 of this variety of L. varium there go both a change in the configuration of 

 the stele and also a tendency towards a greater difi'erentiation of the tissues 

 composing it. The larger girth of the stenis of this particular variety is due 

 to the presence of a very wide soft middle cortex. The outermost, usually 

 thick-walled cortical zone is here very poorly developed, as we would expect 

 from the habitat of the plant. 



The largest variety of L. varium which I examined was that which 

 occurs at Otira Gorge and Stewart Island (fig. 4). In accordance with the 

 size of the plant the stele is even larger than that of the Campbell Island 

 form, and there is a greater disposition towards the formation of phloem and 

 xvlem islands. The typical radiate or stellate disposition of the vascular 

 tissues is thus broken up, but that the stem-anatomy is essentially identical 

 with that of the smaller forms of L. varium is quite clear both from an exami- 

 nation of it as it occurs in the smaller branches and also from an examina- 

 tion of the histology of the several tissues of the stele and cortex. In some 

 of the larger phloem plates in the Otira Gorge plant there is a central row 

 of cells that remain empty and are in clear contrast with the rest of the 

 phloem, which flanks the central row, and which shows abundant contents. 

 This is more marked still in the case of the Stewart Island plant, where the 

 centrally-placed phloem cells are sometimes comparatively large in size. 

 This feature is quite consonant with the robust growth of this variety from 

 the two localities named, and especially with that from the latter place. 

 The outer cortical zone in this variety is strongly sclerenchymatous. In 

 both cases a considerable number of roots appear in transverse section in 

 the middle cortex at the base of the stem, as many as six being noticed 

 ill some sections. 



The stem-anatomy of L. Selago in all the varieties in which it occurs in 

 New Zealand corresponds closely with that described above for the smaller 



