SEAT OF VEGETABLE LIFE. 



Fig. 44. 



141 



^^"S^^a^ 6 



Sections of a stein as it appears in May or June of the fifth year. 

 he white spaces show the swelling cambium. 



A t". t.nP PTln nf SQTkf OYYll^Y 0-->/1 !*- -->nr\-ir 17-T-M/lrt f*f 



The white spai 



At the end of September, and in many kinds of 

 trees much sooner, the sections appear as in Fig. 45. 



Fig. 45. 



Sections of a stem at the end of the fifth year. The envelope and 

 layers of liber are too thin to be shown by the pencil. 



Here we observe that a new concentric layer of 

 alburnum has been added during the fifth summer, 

 and also an additional layer of liber has been parted 

 off, and placed close to that of the preceding year, 

 and lined on the inner side with an almost imper- 

 ceptible membrane or coating of gelatinous matter, 

 which is the vital envelope, and from which the new 

 growths of wood and liber of the next, and all suc- 

 ceeding years will be produced. 



