THE STEM OR SHOOT. 



107 



part, where the plant was moist and shaded ; in the 

 upper part the rhizophores were invariably replaced 

 by typical leafy shoots which appeared always on the 

 upper surface of the stem ; 1 saw no transitions 

 between them and rhizophores, but their position 

 showed clearly that they represented the latter. 



" I have also observed rhizophores in the form of 

 leafy shoots in the following species, besides the two 

 above-mentioned : S. Wildenovii Baker, 8. canaliculata 

 Baker, 8. serpens Spring, and 8. grandis Moore. In 

 the first-named I saw a rhizophore in the form of a 

 branched leafy shoot quite a foot high ; in the last- 

 named (8. grandis) they are in the form of small, 

 flower-like structures, as described by Groebel." 



" Bruchmann found in the case of S. Kranssiana 

 A.Br, that by cutting off the two arms of the stem- 

 fork at an early stage of the development of the 

 rhizophore, . . . the apical cell of the rhizophore 

 becomes that of a leafy shoot and the latter becomes 

 the direct continuation of the former. ... I 

 myself performed a similar experiment to that of 

 Bruchmann with stems of 8. insequalijolia, and S. 

 Mettenii, and with similar results. 



" From all the above-cited facts it is clear that the 

 leafy shoot in these cases ... is itself a rhizophore ; 

 the appearance suggests unequivocally that the pheno- 

 menon before us is not a case of a normal rhizophore 

 being first formed which then gives rise, by transfor- 

 mation of its apex, to a leafy shoot; on the contrary, 

 it is clear from direct observation that there is only 

 one organ here present. The cases of Neottia, Listera, 

 and Anihurium are not to be regarded as parallel, for 

 in these there was a clearly-defined organ, viz., the 

 root present in the first instance, whose tip developed 

 suddenly into a leafy shoot, without any transition 

 between the latter and the root ; it is most obvious that 

 there are two distinct organs present ; the terminal 

 shoot in these cases is almost certainly an adventitious 

 structure which, at first in its origin .lateral, has 



