203 



The other shoots were ail more or less différent from the normal scheme, they 

 showed the following conditions. 



Number 4 had one trimerons whorl, an agglomerate of two regular alternatmg 

 trimerons whorls and in the centre of this agglomerate one odd leaf . 



Number 5 had one regular trimerons whorl, then one single leaf, placed between 

 the orthostichies of two leaves of the lower whorl, and then a terminal agglomerate, 

 consisting of two leaves which formed a complète trimerons whorl with the lower 

 single leaf, two regular alternating trimerons whorls and lastly one single leaf in the 

 middle, in the position ot one leaf of an alternating trimerons whorl. 



Number 8 had one normal trimerons whorl, and a terminal agglomerate of one 

 reguiar trimerous whorl and one of two leaves; the last standing in the position of 

 two of the leaves ot a trimerous whorl. 



Number 15 with only a terminal agglomerate of 8 leaves was by no means 

 tetramerous, but had two regular trimerous whorls and a third whorl of two leaves, 

 standing in the position of two of the leaves of a trimerous whorl. 



Number 16 was also trimerous, the lowest whorl consisted of a regular trimerous 

 whorl with the addition of one leaf, placed somewhat higher between two of the 

 tliree; the terminal agglomerate at first contained two leaves, forming a second 

 trimerous whorl with the odd leaf below, and further on a third trimerous whorl 

 and two leaves of a fourth one. 



Number 17 possessed one basai trimerous whorl, a second which was divided 

 into one single leaf and two placed together higher on, then a third regular whorl 

 and a terminal agglomerate of 3+3+ 1 leaf. 



Number 19 had a lowest whorl of 3+1, then two leaves forming a regular 

 alternating whorl with the lower odd leaf; the rest was regular trimerous. 



Number 21 was quite regular trimerous, except a seventh odd leaf in the centre 

 of the termmal agglomerate. 



Number 22 was just as regular tetramerous, only one leaf of the second 

 whorl was displace d to the first whorl. 



From the foregoing our conclusion must be that P. verticillatum 

 has origlnally a whorled phyllotaxis with crowded whorls; that 

 when elongation begins it takes hold în many cases ot the internodes 

 between the whorls, and a regular whorled condition is arrived at, 

 in other cases the elongated parts of the stem are other irregular 

 oblique zones, and the resuit is that the numbers of the whorls 

 seem to te changed. 



The term growth whorl may quite well be applied to this case; the 

 peculiar distribution of growth is hère quite the same as inLiliitmMar' 

 tagon, it is only applied to another preexisting arrangement of leaves. 



5* 



