48 



Principles of Plant Culture. 



used by the plant are not taken in to the same extent as 

 those that are needed, because their equal distribution is 

 less disturbed. 



The distribution of soluble matter in the plant is also 

 promoted by transpiration (75). 



SECTION IT. THE INNER STRUCTURE or THE PLANTLET 



Thus far, we have considered the plantlet mainly from 

 the outside. Before going farther, it is well to learn also 

 something of its inner structure. We have seen that all 

 parts of the plant are made up of cells (12) and that 

 these cells differ in form and office in the different parts. 

 The cells of the leaf, for example, are different in shape 

 and in the use they serve to the plant, from those of the 

 stem, flower or fruit. 



65. The Epidermis (ep'-i- 

 E P- der'-mis). The plant is cov- 

 ered by a thin, translucent 

 skin that extends over the en- 

 tire surface of the leaves, stem 

 and root, called the epidermis 

 (Fig. 17 Ep.). This skin is 

 formed of comparatively 

 thick walled cells and serves 

 to protect the more delicate 

 Ep parts within. It may be 

 FIG. IT. showing section through readily withdrawn in some 



leaf of Oldenburgh apple. Ep. ep- plants, as from the leaves of 

 idermis; Pal. palisade cells; J in- 

 tercellular spaces. Highly magni- the liveforever * and echev- 

 fied. See also Figs. 13 and 20. 



Pal. 



er j a | ail( J young Stems of the 



plum. The exposed surface of the epidermis of the 

 leaves, fruit and young stems of many plants is trans- 



* Sedu m teleph ium. f Cotyledon . 



