

195 



They described the resulting whorls as quite regular; the partial 

 growth of the axis should therefore hâve set in at a very early stage 

 and the members of the future whorl should hâve been so little 

 developed as to be stlll liable to be arranged in a regular whorl. 

 It is very probable that in many plants this may be the case, but as 

 y et it has nowhere been proved. 



In the above considered case on the contrary, the growth of the 

 axis is not altered before the primordia of the leaves are well devel- 

 oped; the arrangement of the numbers of the ,, whorl" remains 

 the same, and the original phyllotaxis may easily be read even from 

 the adult condition. 



The distinction between growth and other whorls is not identical 

 with the familiar distinction between true and false whorls. Growth 

 whorls are a kind of false whorls, but it is by no means sure that 

 the other whorls are ail of the same kind and are ail to be termed 

 „true whorls". 



3. Ferula thyrsiflora Sibth. et Sm. In this umbelliferous 

 plant we shall corne across a case of whorled phyllotaxis, that 

 shows the greatest analogy to that of Lilium Martagon just des- 

 cribed, in the higher cauline leaves and the lower bracts of the shoot. 



The mflorescence of Ferula of course is a compound umbel; 

 but this compound umbel is only part of a much larger mixed 

 inflorescence, which might be called a compound raceme (panicle) 

 of compound umbels, in which in main axis and first order of 

 latéral axes the bracts are placed in more or less regular whorls. 



Of thèse shoots^ I examined 5 spécimens. Of the main axis of 

 one of thèse I made flg. 2, in the same way as in which fig. 1 of 

 Lilium was drawn. 



The first four leaves show clearly a left-hand ordinary spiral, 

 the leaves 5 — 8 are already contracted into a kind of whorl ; 9 — 1 1 

 however show the same left-hand spiral and are just placed in the 

 spots required by that spiral. Leave 12 — 18 form again a conglo- 

 merate; 14 and 17 are placed somewhat higher than the rest. When 

 we follow the „genetic" spiral, we come across some „negative" 



^ From no. 8971 of the Garden Catalogue. 



