190 



The same peculiar heteromery seems to occur in the two other 

 Lilies, mentioned above; one of the figures in Curtis^ shows a 

 shoot of L. canadense with three successive whorls of 6, 3 and 4 

 leaves; and a spécimen of L. Superbum in the Groningen her- 

 barium^ has two successive whorls of 10 and 8 leaves, 



There are however also cases, viz. in L. canadense, in which no 

 whorls occur at ail, but ail the leaves are scattered on the shoot; 

 this appears from the description (foliis sparsis et verticillatis^) and 

 from a figure^. 



From the foregoing it would seem, as if we had hère a peculiar 

 whorled phyllotaxis, which was not to be explained further in any 

 way. A doser examination however, soon shows, that this whorled 

 condition has ansen from a normal spiral phyllotaxis in a very 

 simple and conceivable way, viz. by a very unequal growth of the 

 parts of the stem between the leaves, some remaining undeveloped, 

 whereas others attain a considérable length. 



To give an adéquate idea of the position of the leaves on a whole 

 shoot of L. martagon, I hâve drawn fig. 1, which gives a représen- 

 tation in Y^ natural size of the above shoot no I , divided into six 

 successive parts. In the middle of each part a dotted line marks 

 an orthcstichy of the stem (which was in reality a little twisted, in 

 an irregular way, but which showed by the course of its fibres how 

 the original orthostichy was to be followed). 



1 1. c. XXI. 1805. t. 800. 



^ from Biltmore Herbarium, 2651b. 



3 Curtls 1. c, CI, 1875, t. 6146. 



