42 BOTANY. [CHAP. i. 



similar cells that remain organically connected, the result 

 is a tissue ; and when these cells are morphologically 

 (structurally) and physiologically (functionally) of com- 

 paratively equal value, being furnished with comparatively 

 thin walls, and not much longer than broad, the tissue is 

 called cellular or fundamental tissue. Some groups of 

 plants, as Algae and Fungi, are composed entirely of 

 fundamental tissue, and have consequently been called 

 cellular plants, whereas all other groups of plants, on 

 account of the presence of other tissues in addition to 

 fundamental tissue, have been called vascular plants. 

 Fundamental tissue constitutes the starting point of 

 every plant, however highly differentiated it may become, 

 and is also indispensable at every stage of its existence, 

 inasmuch as it is the only tissue possessing the power of 

 growth or of adding to the bulk of the individual by 

 cell-division, consequently where growth is taking place 

 is a certain sign of the presence of fundamental tissue, 

 as the tips of stems, roots, etc., such portions are called 

 growing-points. 



The trunks of all forest trees in the earliest condition 

 consist of fundamental tissue, the outer layer having 

 become differentiated into an epidermis. The fibro- 

 vascular bundles present in the stem originate in the 

 young leaves that appear at first as very minute papillae 

 or outgrowths arranged round the growing-point or 

 apex of the stem which they protect by being arched 

 over it during the bud stage. In the bud state the 

 youngest leaves are so near the apex of the stein that 

 they might probably be considered, on a superficial 

 examination, to originate from the actual apex of the 

 stem. Such, however, is not the case ; there is no such 



