194 



The whorls are formedby 10—24 and 25—35; the adjoining internodes are very 

 long, just as the internode between the last stérile leaf and the first bract, AU this 

 is exactly as in the first spécimen. The leaves 36—43 were stérile, 44—54 floriferous 

 bracts. 



A third spécimen with again a just as regular right-handed spiral showed also 

 similar conditions: 



The first whorl is hère 8—20, the second 21—33, the stérile leaves were 34—42, 

 the bracts 43—54. 



In the zone of the stérile scattered leaves there are hère three , .négative inter- 

 nodes", but apart from this, the most stnking feature in the given figures is the 

 close similanty to those of the two preceding stems. Considering the objects them- 

 selves, it is impossible not to recognize the regular spiral phyllotaxis, out of which 

 the whorls are formed, the first leaf of the whorl lying just in the position pres- 

 cribed by the lower leaves, 



This kind of whorl, which simply anses by a pecuhar kind of 

 growth of the axis may be called growth whorls. 



The idea, that whorls may arise by excessive growth of certain 

 parts of the axis is by no means a new one. In the introduction I 

 hâve already pointed out that Se h imper and Braun took ail 

 whorls as contracted spirals and Del pi no devoted several chapters 

 of his ,,Teoria générale délia fillotassi"^ to the ,,sviluppi interno- 

 dali regolari ritmici"^ that gave rise to false whorls. 



In ail thèse cases, however, it was mère spéculation without any 

 conclusive évidence of the truth of the enounced opinions. 



1 Atti R. Univ. di Genova, Vol. 4, p. 2, 1883. 



2 1. c. p. 295-304. 



