140 



PLAKT STUDIES 



if necessary, the parts of tlic leaf or tlie stem itself twisting 

 to allow the blade to assume this position. The danger of 

 the leaves shading one another is reduced to a minimum Ijy 

 the elongation of inteniodes, the spiral arrangement, short- 

 ening and changing direction upwards, or lobing. 



This outlines the general nutritive relations, the roots 



Fig. 14'iii. Germiiiatiim of tlu' pardon Ik'uti, sliowine the arch of the seedling ptein 

 above proimrl. ilw jaill on the peed hi extrieati' tlie cotyledons and ]ilinnnle, and 

 tlie final strai^ditenlng of the stem and expansion of the \onng leaves.— Alter 

 Atkinson. 



and leaves lieing favorably placed f(.)r alisorption, and the 

 latter also favorably ])l;ieed for photosynthesis. 



98. Placing of flowers. — 'I'he pui'itoses of the llnwer seem 

 to be served best bv e.\posed positions, and conse(|uentlv 

 Ilowers mostly appeal' at, the extremities of stems and 

 branches, a ]H>sition rviilenlly favoralile to ])ollination and 

 seed dispersal. The Ilowers thus exposed are very com- 

 nionly massed, or, if not, the single llowei- is a.pttol)e largi' 

 and i;onspictnms. The various devices for ]>roteeting nec- 

 tar and pollen against too great moisture, and the more 



