The Significance of llic .Atai'isls. 



559 



ginning of the spiral accurately in sonic cases In mark- 

 ing and counting the pairs of leaves, as they made their 

 appearance, from the moment of germination. But T 

 have not yet plotted a curve from data collected in this 

 extremelv lahorious wav. On the other hand the numher 

 of straight internodes ahove the torsion can easih' he 



O r 



Fig 132. ]^a\criana ofhc'maWs. A stem witli a local tor- 

 sion, from the same culUire as Fig. 122. (June 1900.) 



counted; and their numher ojjviously varies inversely 

 with the extent of the twisted part. 



Tn 1900, when my eighth generation consisted of 

 1295 flowering plants, T recorded tlie numher of straight 

 internodes ahove the torsion in everv twisted stem. Omit- 



