APPLICATION OF VORTEX CONSTRUCTION. 



49 



vertical one, and the plant is at liberty to choose either construction 

 along two sets of orthogonally acting lines of pressure in the same 

 system. 



4. Arrangement C. 



Such an arrangement, the familiar case of " alternating whorls^' 

 is, in fact, the one found in the vast majority of symmetrical plant 

 constructions. It presents all the advantages of a "condensed" 



Fig. 21. — " Concentration " system. 



system, in that the same number of elements is so arranged that 

 it is shorter longitudinally and broader transversely. The geo- 

 metrical construction of fig. 21 shows that in such a simple case 

 the shortening of the system will represent a vertical gain of 

 6 : 3 72 :: 2 : J2 :: 100 : 70-7, or a gain of up to 30 per cent, as 

 expressed in the number of internodes which can be laid down 

 on a given apex. 



Without insisting on any such biological interpretation, as that 



