74 



PLANT STUDIES 



KiG. G4. An .'iraiicilriali pine, phowiiiL^' the 

 ceiitr:d shaft, uiid tlic res,Milur cliit^tiTy of 

 braiiclii-s sjircanini^f in rvfry (Iir(H-liuii anil 

 bearini,' mimrmiis h^inall lra\is. The low- 

 ermost liraru'lli-H <>\lrinl tinw iiw alHs ami 

 are the larp'st, wliilc Uuit^r al)o\(' iHaMniir 

 more horizontal ami sinalUT. 'I'lioc dit- 



fcrnic-cs ill tlic n\/r and diiTcti if the 



braTichcs secure the largest light <-xpo- 

 gure. 



are of this character ; 

 and as tlic iiitiin pur- 

 pose is food sl()r;i.i,'e 

 the most f:ivor;ihle 

 position is a stiljter- 

 raiieau one (see Fig. 

 CiCi). Soiiietinics siK'li 

 sctihi h'tives hecoiiic 

 very hrotid timl not 

 merely ovcrhtji hut eii- 

 wrtip one tiiiotlier, as 

 in the ctise of tlie 

 onion. 



51. The tuber type. 

 — Tlio ordinary pottito 

 may lie ttiken tis tin il- 

 Instration (see Fig. 

 (17). The minnto settle 

 Ictives. to he found ttt 

 the ■' eyes ""' of the 

 pottito. do not overhtp. 

 which nietins thtit the 

 stem joints tire I'tirther 

 ajitirt thttn in the htid 

 type. The whole form 

 of the stem resiills 

 from its nse as tt jtlaee 

 of food stortigc. tiiid 

 heiie.e sticli stents are 

 generttllv suliteri'tt- 



netin. hood stortige, 

 snlil errtincan ])nsit ion, 

 tliid red need settle 

 lettves tire fticis -whii'h 

 seem to follow ettch 

 other ntttiirtiUy. 



