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7. Discussion. The hère descrîbed cases hâve ail this in common 

 that a stem with origiricJly crowded leaves is divided by an unequal 

 growth into bare and into leafbeanng parts. 



Thèse leafbearing parts assume in this way a certain resemblance 

 with whorls, and in some cases they hâve been described in the 

 literature as whorls. 



It is clear that thèse formations, to which we hâve given the name 

 growth whorls are to be considered as a kmd of false whorls, and 

 that nothing is yet said about the nature of true whorls nor of other 

 false whorls, as they occur in flowers. But it seems to me that before 

 the problem of whorl-formation in the vegetable kingdom can be 

 properly laken in hand* it will be useful to seclude from the rest 

 of the whorls the formations which hâve been described hère and 

 which form clearly a kind of secondary transformations, originating 

 only late in the development of the shoot. As to the way in which 

 this distribution of growth is determined 1 can give no indications 

 as yet ; we may perhaps make only the foUowing remarks. 



In the Umbelliferous plants the formation of the umbels dépends 

 upon a stunted growth of the internodes between the rays; the 

 growth whorls of the leafy stem of Ferula may therefore hâve 

 ansen from a mixture of the factors that cause the ordinary growth 

 of the internodes of the stem and of those that cause the stunted 

 growth in the umbels; it would therefore be a partial spreading 

 of a factor, that ordinarily only acts in the inflorescence, to the stem. 



In Primula we hâve in the same way the contrast between the 

 vigourous growth in the majority of the species of the basai part 

 of the flowershaft and the stunted growth in the terminal umbel; 

 in most species thèse two processes are quite separated and the 

 resuit is a single umbel. In others they are intermixed as we hâve 

 seen, so that they form growth whorls; a third category is formed 

 by those species as P. acaidis, where there is no flowershaft at ail 

 („scapus nuUus") but only a sessile umbel between the leaves. 



It is clear however, that thèse considérations give not yet the 

 explanation of the phenomena, and in the other cases not even this 

 partial comment can be given. 



