54 



THE PLANT CELL. 



For the purpose of studying the structural details of the 

 cambium both transverse and longitudinal sections should be 

 taken of the stems and roots selected. In transverse section the 

 layer has much the same appearance as the cork-cambium, each 

 cambial element having a somewhat flattened rectangular shape, 



•^J5 



Fig. 37. —A Longitudinal Section through 

 THE C.4MBIAL REGION ov ]lnca major 

 (stem). — X X X, Cambial cells ; ph, young 

 sieve-tubes of the phloem ; pr, phloem- 

 parenchyma ; a^i, young wood elements 

 (pitted traoheides); xy.^, older woorf- 

 elements. 



Fig. 38 (semi-diagram- 

 matic). — A Longi- 

 tudinal Sectiok 



THROUGH the CaM- 



BiAL Region or 

 Pinus. — Cj, Cj, Cj, 

 Cambial elements ; 

 Ci remains active, c, 

 and c-i going to form 

 xylera and phloem 

 elements respec- 

 tively. 



and in careful preparations the protoplasm is seen to fill the cell- 

 cavity almost entirely (see Figs. 36 and 36a). In longitudinal 

 sections (see Figs. 37, 38, and 39) each cambial cell is observed 



