( ^) 



I will (irst show hv a, few exninplcs thai the piosenee of the 

 organs on tiie top is necessaiT in ordei' to cause tiic stem to grow 

 norniall}' in length. 



Tlie stem of' an Erantlm was on February 4, 1905, 40 mui. long, 

 measured from the base near the rhizoma to the Junetion of the 

 leaf-whorl. Placed in the hothouse the plant was at tirst measured 

 daily, afterwards every other day ; for briefness' sake 1 shall liei'e 

 only give the lengtii reached by the stem after every four or live days. 



In the same time the development of a stem on which leaves and 

 flower had been cut away, was: 



Date 4.2 8.2 13.2 17.2 

 Length 49 52 54 55 



Another example of growth with a normal stem: 



and of a stem, bereft of lea\'es and flowers: 



Date 5.2 9.2 13.2 17.2 

 Length 97 103 104 104 



Whereas with normal Eranthis-stems the to|) with llic (lower on 

 it, had in the hothouse after a couple of days, entirely erected itself, 

 on the other hand the hook-shaped curvature of the stem without 

 flower or leaf-whorl, partially remained and it was only very slowlv 

 that its extremity raised itself to some extent. This need cause no 

 wonder, if it is remembered that the disappearance of this curvature 

 is caused by asymmetrical growth of the top of the stem. 



Now in a series of Erantlm plants the organs on the top of the 

 stem were only partly removed; e.g. the three greeii leaves, the 

 petals, the stamens, the pistils. The length of the stems was measured 

 from day to day. The result (.)f these experiments has been very 

 clear. As long as the green leaves remaiiied undamaged, the growth 

 of the stem might be called normal. At the utmost tlie stem remained 

 a little below its normal length if the whole flower or certain parts 



