22 PLANT STUDIES 



general outline of such a plant, therefore, is usually not 

 conical, as in the other case, but cylindrical (see Figs. 4, 

 15, 10, 22, 45, 83, 90, 101, 174, 178 for brunched leaves). 



Many other factors enter into the light-relation of foli- 

 age leaves upon erect stems, but those given may suggest 



Fig. 16. A cycad, showing much-bran cheil leave's and palm-like baliit. 



observation in this direction, and serve to shov that the 

 arrangement of leaves in reference to liglit de])eiids upon 

 many things, and is by no means a fixed and inditferent 

 thing. Tiie study of any growing plant in reference to this 

 one relation presents a multitude of proldenis to those vvlio 

 know how to observe. 



I'l. On liori-jinliil sirms 



23. Examples of hurizoutal sleiiis, (liat is, stems exposed 

 on one side (o tlic direct light, will lie fcund in tlu^ case nf 

 many branches of trees, stems prostrate on the ground, and 



