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Cutting the membrane on the right sight and turning it ovei* 

 to the left we get a view inside the flowertube and at its 

 hindwall (fig. 4). This hind wall is formed by a membrane which 

 is stretched between the style S and a rudimentary idem s-\ 

 There is only a very thin third wall, limited by the two rudi- 

 mentary styles s and s\ Transverse sections of the tube show 

 the same thing in different stages. Cutting the tube near the 

 base we get a section as represented in fig. 5, viz. a quadrangular 

 space on the right side of which the style ^S is to be discerned. 

 In fig. 6 we see almost the same, only the canal of the style >S' 

 is better defined and the dotted segments indicate the distribu- 

 tion of the vascular bundles in connection with the parts of 

 the flower which are about to differentiate higher up. 



In fig. 7 one can distinguish both the semi-anther x and the 

 labellum detaching themselves from the outer wall of the tube 

 but at the same time a considerable shrinking of the latter. 

 Fig. 8 shows a farther stage of the process. In figures 9 and 

 10 which again correspond with higher sections, the hind wall 

 is seen to withdraw from S, through which fact the central 

 canal flows together with that of ,r. 



Fig. 11 deserves attention on account of a differentiating it- 

 self from the wall of the tube and the back wall reduced to 

 a small pointed excrescence. A little way higher up (fig. 12) 

 the front wall also falls off and will soon have disappeared 

 altogether. 



From the above we get at this conception : by removing from 

 a Canna-flower the calyx and as far as possible the petals and 

 the outer alae /?, y and 3, again by cutting away the parts 

 of the innerwhorl : «, labellum and .t, we leave the ovary crowned 

 by three styles which are united by means of membranous 

 walls and thus enclose a quadrilateral cavity, of which two 

 parallel faces are much wider than the tw'o other. The two 

 wide faces connect S respectively with ,v and .y', one of the 

 smaller faces connects s with s', S itself constituting the fourth. 

 This cavity splitting up into one big broad winged style S 

 and two rudimentary ^^ and / is to be looked upon as the 



