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supernumerary buds in the axils than with /. tomentella, and 

 furthermore no branches are developed. But never-the-less the 

 buds which correspond in position to those which in /. tonien- 

 tella develope into branches, grow to a considerably larger 

 size than the rest of the abortive buds , so that this difference 

 between the plants does not seem important and indeed the 

 less so as the branches of /. tomentella have a very limited 

 development, soon dying and falling off. The position of the 

 tendrils and the occurrence of the larger buds exclusively upon 

 two neighljoring orthostichies is just as in /, tomentella. Con- 

 sidering this close systematic and morphological resemblance 

 of the two plants, it is to be expected that the stems will in 

 anatomy as well present the greatest similarity , and indeed , 

 so far as the tissues of the normally oriented libro-vascular 

 zone are concerned , this is true. The peculiar ring of first- 

 formed secondary wood , the lobes of hard wood standing oppo- 

 site each other and the intermediate areas of soft xylem cor- 

 respond accurately to those described above, the only diffe- 

 rences to be noted being that the areas of soft xylem just 

 mentioned , grow but little in thickness and show less tendency 

 with the increasing size of the stem to assume a normal 

 development than with /. tomentella', and that in consequence 

 of this, stems of /. ovalis even when they attain a consider- 

 able age are still strongly elliptical, or even flat on opposite 

 sides. 



If however the attention be directed to the pith, it will be 

 found that all analogy between the two plants suddenly fails. 

 The medullary tissue of /. ovalis is entirely normal and shows 

 no sign whatever of the remarkable anomalous structures so 

 conspicuously developed in /. tomentella. This is a truly re- 

 markable difference in the anatomy of the stems and cannot 

 but seem in spite of morphological resemblances to raise much 

 doubt about the correctness of classing the two plants as 

 varieties of the same species. As we have seen , the cambiums 

 in the pith of /. tomentella arise by a gradual extension of 

 the normal cambium through the openings in the vascular 



