THE BOOT. 



67 



Lateral roots which, under normal circumstances, 

 are but little or not at all developed, can be induced 

 to do so by artificial mutilation, as by excision, of the 

 apex of the main root. Goebel describes and figures 

 a case in the Ternstroemiaceous plant Norantea 

 guianensis in which a species of sympodial branching 

 was induced in the long branchless descending aerial 

 roots by the excision of the apices of the main root 

 and the successively -formed lateral roots ; and he 

 describes the same kind of thing for the aerial roots 

 of Vanilla (PI. V, fig. 4) and Monstera, and in the 

 root of the broad-bean seedling. Miss Chandler 

 describes aerial roots of Tibonchina whose tips died 

 away, causing a sub-apical profuse formation of lateral 

 roots, and sometimes a fasciation-like flattening of 

 the tip. 



Forking and Fasciation. 



The various cases known of palmately-divided tap- 

 roots, in the carrot, turnip (Bmssica Bapa) (fig. 18), 

 radish (Baphanus sativus), 

 and parsnip (Pastinaca sa- 

 tiva), would seem, from their 

 appearance in the mature 

 condition, to be due to fas- 

 ciation (see infra under 

 Stem), as the thick basal 



•portion Of the main rOOt is FlG - ^.—Brassica Bapa. Abnormal 

 t • t i , , i -i "i lateral branching, probably due to 



divided lip at the apical end abortion of the main root. 



into a number of branches. 



But this condition might quite well have been brought 

 about by the early abortion or dying away of the main 

 root, causing the rapid and equal development of a 

 number of lateral ones, the original mode of growth 

 becoming obscured in the mature structure. 



Fermond describes forked roots in the turnip, 

 fennel (Foeniculum vulgare), and salsify (Tragopogon 



