THE PLANT-BODY. 69 



generally wanting in chlorophyll-bearing tissue, and with 

 generally a more delicate texture. 



(5) Stamens, in which a portion of the soft tissue devel- 

 ops male reproductive cells (pollen). 



(6) Carpels, bearing or enclosing female reproductive 

 organs (ovules). 



(7) Tendrils and (8) Spines, which are reduced or de- 

 graded forms, composed of the modified fibro- vascular bun- 

 dles and a very little soft tissue; in the first the structures 

 are weak and pliable, in the latter stout and rigid. 



The altogether special modifications of the phyllome, as 

 in pitchers and cups, will be noticed hereafter. 



123. Eoot. — The root is that portion of the plant-body 

 which is clothed at its growing point with a root-cap. In 

 ascending through the vegetable kingdom roots are the 

 latest of the generalized forms to make their appearance, 

 and in the embryo they appear to be formed later than 

 caulome and phyllome. They present fewer variations 

 than any of the other generalized forms. The ordinary 



(1) Subterranean roots of plants are typical. They differ 

 but little from one another in whatever plants they may 

 be found. 



The other root-forms are : 



(3) Aerial roots, which project into the air, and often 

 have their epidermis peculiarly thickened, as in the epi- 

 phytic orchids. 



(3) Roots of Parasites, which are usually quite short, 

 and in some cases provided with sucker-like organs, 

 by means of which they absorb food from their 

 hosts. 



124. Trichome. — The trichome is a surface appendage 

 consisting of one or more cells usually arranged in a row 



