u. 

 Plato I . 



Fig. 1. A nearly vertical section of 1 ho ci em apex 

 s}ioY/ing the sm^face of the stem cmd the iei.f mother cell 

 witli one ser;nient v/all. x300. 



Fig, 2, TrtmsverGO sGction of stem throw';h apical 

 cell of yoimg leaf. x300. 



Fig, 3, Section of stem "between vertical ajio. hiori- 

 aontal planes, sh-ov/inr^ si;j*face of sten apex and transverse 

 section of leaf. x300. 



Fig. 4. Sagittal section of a leaf nea.rly at tlie end 

 of apical grov/th. x200. 



Fig. 5. Part of a sagittal section of the petiole of 

 an older leaf. x300. 



Fig. C. Ventral surface of tip of cfjji Yovnr; leaf. x400. 



Fig. 7. Dorsal surface of th.e tip of a similar leaf 

 x400. 



Fig. 8. Surface of the tip of a very yomxr; leaf sliov;- 

 in;: the edges of the two youngest segments on one side 

 and th.e apical cell seen so as to show th.e shape C'f its 

 lateral wall and hence tl.u uii..i>L.- of the s- -- "-s also. xVrO. 



Fig. 9. Half of a nc 'r;Jisver6e section of a 

 young leaf, shov/ing thie siiapa o- a uuj;.uiiL L.iv.. th.e pos?.- 

 tion of th*^ fii'st s cti'.n v/v.ll. x7r0, 



Fip. iO, A similar section siio inr a?^ older sef-Tneii ... • 



