42 



THE iioor 



sap, fasten their roots undergrouiKl upon the roots of neighboring 

 pihmts, and rob theni of tlieir juices. 



62. Rcots as holdfasts. —T 



function comes to be 

 of great importance as 

 the [ilauls become tall 

 and liave to stand 

 against tlie violence of 

 the winds. And so 

 the main roots of a 

 tree, spreading abroad 

 nndergi-ound, corre- 

 spond in girtli with 

 the largest of the 

 branch trunks spread 

 in the air above. 

 They increase, like the 

 trunk and limbs, by 

 the annual formation 

 of wood. Yet notwith- 

 standing their great 

 size and strength, 

 every heavy A\ind 

 storm leaves here and 

 there a tree over- 

 turiu'd. 



63. Roots for climb- 

 ing arc well shown by 

 the Trumpet Creeper 

 (Fig. 34). Near the 

 nodes, on the sbadeil 

 and moister sides of 

 tlie stem, aerial roots 

 are produced in longi- 

 tudinal idws. and bi'conie matted together like felt by 

 means of the numerous root hairs that cov(M' them through- 

 out. As the young stems of the vine push upward close 

 to the face of a. wall or building, these webs of roots grow 

 out until they strike the stone, when they flatten out and 



32. Dodder j^arasitic on tlie stem ot an lierl). 

 Note the ab.sence of lea^'es (except a 

 few small scales, I), the develoi:)ment nf 

 snckin;^ roots, /;, and the flo^erelusler. 

 Tlie plant lias no connection with the 

 ground, except in the seedling stage. 



