Longitudinal Symmetry in Phanerogamia. 



305 



Table VI. — F 3 from Case 1 in the Mating Crimson Delila x Yellow Crimson- 

 striped. 



Number of 

 individuals. 



Colour of 

 individuals. 



Colours in F 3 . 



Crimson. 



Crimson delila. 



Yellow. 



5 

 3 

 2 

 2 

 2 

 8 





+ 

 + 



+ 



+ 



+ 

 + 



+ 

 + 



+ 



+ 





>> 



„ delila 



Yellow 





Longitudinal Symmetry in Phanerogamia. 

 By Percy Groom, M.A., D.Sc, F.L.S. 



(Communicated by Dr. D. H. Scott, F.R.S. Eeceived January 24, — Eead 



February 21, 1907.) 



(Abstract.) 



The first object of this communication is to put forward a simple graphic 

 method of recording measurements concerning the longitudinal symmetry of 

 plants, and to test its efficiency as a means of solving morphological problems. 

 The method is as follows : — Measurements of the successive internodes of a 

 stem are made, and are recorded on squared paper as successive ordinates ; 

 the resultant curve is termed the internode curve. The longitudinal distances 

 apart of other members are dealt with in the same manner, and ranged into 

 other curves. 



The second object of the paper is to describe the general and particular 

 results obtained by use of the method. 



In a typical herb, the internode curve of the main axis is a regular and 

 characteristic ascending-descending one (see Curve 1 in fig. 1), while those of 



3 

 Fig. 1. 



