38 



EAST LESSONS IN VEGETABLE BIOLOGY. 



cambium, (Sec. 2 3 ) in which, thin-walled cells become 

 transformed into vascular or bast-cells, (Sec. 4,) and 

 these are changed into permanent cells. Groups 

 of cells are thus formed which, united into bundles, 

 penetrate the rest of the tissue, forming the fibro- 

 vascular bundles. The development of these bundles 

 is characteristic of different types of plants. The 

 simpler types have no fibro-vascular bundles, and are 

 called Cellular Plants / the rest are termed Vascular 

 Plants. 



9. The fundamental tissue generally consists of 

 thin-walled cells containing starch, although other 

 forms of cells may be present. In plants which have 



no fibro-vascu- 

 lar bundles the 

 whole interior 

 may be regard- 

 ed as funda- 

 mental tissue. 

 In other plants 

 it fills up the 

 spaces between 

 the bundles and 

 within the bark. 

 In the type of 



FIG. 14. 



Endogens (Ch. 



IY, Sec. 5) this tissue is most developed, while in Ex- 

 ogens it occupies a smaller portion of the structure. 



