370 Mr Philip Sewell's Observations upon the 



intermediate group, in which, although the species possess no 

 evident internodes, yet the leaves are long, petioled and 

 erect : — 



Table C. 



That a better comparison may be made as to this 

 difference in habit, we have given the heights in millimetres, 

 as measured on the 130th day, to the tip of the most erect 

 leaf in every case. Where drawn out because of competition 

 among the individuals, we have placed a mark ( -)- ) after the 

 name ; and in order that comparison may be clearer, we have 

 inserted the number of the days which elapsed till each 

 species germinated. 



The difference in height is very apparent between the 

 species enumerated in Table A. and those of Table B. 

 Seedlings of >S^. Forskohlci and of S. Tenorii, growing near the 

 edge of those which were crowded together in the pots, 

 possessed leaves as closely appressed to the surface as was 

 the case in S. ceratophi/Ua. It was otherwise with the 

 individuals of these species which were crowded together. 



Although S. interrupta and >S^. canariensis (on Table C.) 

 appear to have the most conspicuously erect habit of all the 

 species, their excessive height is due to the greater develop- 

 ment of their leaves and leaf-stalks, the internodes in 

 S. interrupta developing somewhat later. Often, indeed, 

 where internodes were developed, the leaves were borne 

 almost horizontally, and on this account the measurement of 

 " heights " is fallacious. 



Intimately associated with this development of internodes 

 was the development of huds in the axils of the leaves, and 

 even in the axils of the cotyledons of certain species, at an 

 early stage of the plant's growth. 



In S. aurita, although the second pair of leaves of the 

 primary axis were but 6 mm. in length, these were 

 conspicuous in the axils of the cotyledons on the 50th 



