279 
Growth of Roots and Shoots. 
The general conclusion to be drawn from my experiments 
is that, in the seedlings of the species employed, the growth 
of the roots and that of the shoots proceed with a high 
degree of independence. 
In Zea Mays> the dry weight of the roots at the end of 
the experiments was, on the average, very much the same 
whether the shoots had been repeatedly removed or whether 
they had been allowed to remain. The same is true of the 
shoots with reference to the presence or absence of the roots. 
In Vicia Faba , the primary shoots of those plants whose 
roots were removed could be readily observed to have at first 
developed more vigorously than the primary shoots of those 
plants whose roots were not removed ; whereas at the close 
of the experiment the contrary was the case, as is clearly 
proved by the very considerable difference between the gross 
weights (4. p. 275). The roots of those seedlings of Vicia 
Faba , from which the shoots were removed, showed, in the 
three last experiments related above, no diminution : on the 
contrary, the average weight of the roots formed is rather 
greater than in the case of the intact plants (Series 1). 
The remarkable independence of development of the roots 
was apparent in other experiments made with the object of 
ascertaining, in seedlings of Zea Mays , Phaseolus multiflorus , 
and Vicia Faba> to what length the roots would grow in water 
when the primary shoot and all subsequently developing 
shoots were removed. In Zea Mays 1 the roots attained 
a maximum length of 630 mm. ; in Phaseolus multiflorus , 
a length of 661 mm. ; in Vicia Faba , a length of 718 mm. 
An experiment was also made with seedlings of Vicia 
Faba , to ascertain the effect of removal of the roots ; the 
seedlings were placed in moist garden soil, and were kept 
in the cold greenhouse. Although this experiment involved 
considerable disturbance of the seedlings in consequence of 
1 In Zea Mays , Van Tieghem (Ann. d. Sci. Nat., Bot., Ser. V, t. 17, 1873, p. 217) 
has already observed that in mutilated seedlings, which retained only the 
scutellum, there was a considerable development of roots, without any regeneration 
of the plumule or leaves having taken place. No measurements are given. 
U 
