374 True. — On the Influence of Sudden Changes of 
That the radicles were strongly affected by the solution is 
seen in the forms they assumed. Swellings appeared near 
the tips, and the ends tapered suddenly to sharp points. On 
the other hand, the growth in thickness was much greater 
than normal, the radicles above the swellings reaching the size 
of large radicles of Vicia Faba of the same length. 
A similar but very much more decided effect is noted by 
Wieler 1 in radicles of Phaseolus muliiflorus grown in glycerine. 
Stange 2 also mentions similar appearances in radicles grown 
in a medium containing glycerine. 
Roots of Vicia Faba grown in a 0-25 per cent, solution of 
KN 0 3 gave a practically normal growth-curve. 
We will now turn to the experiments bearing on the ques- 
tion as to the effect of sudden turgor-changes on growth. 
Seedlings taken from the sawdust were marked and placed in 
water for a short time, perhaps one or two hours. This gave 
an opportunity for such changes as might arise from the 
modified conditions of water 3 and oxygen supply to take 
place. The roots were then measured, and transferred directly 
to the desired medium. Those placed in saltpetre solutions 
were allowed to remain for various lengths of time, from 1 to 
72 hours. At the expiration of these periods of exposure, the 
return to water was suddenly made. Care was always taken 
that the same temperature prevailed in the different mediums. 
About 30 minutes after a change of substratum, measurements 
were made to ascertain the amount of elastic contraction or 
elongation due to turgor-change. Further measurements 
were made at suitable intervals to obtain growth-rates. 
Those experiments involving the most decided changes are 
considered first. 
In Table IV are given the average growth-rates of a series 
of roots of Vicia Faba during an exposure of 72 hours to 
1 Wieler, Ueber Anlage und Ausbildung von Libriformfasern in Abhangigkeit 
von ausseren Verhaltnissen, Bot. Zeit. 1889, p. 250. 
2 Stange, loc. cit. 
3 Compare Duhamel, Naturgeschichte der Baurne, Bd. I (1764), p. 107. 
Sachs, Gesammelte Abhandlungen, Bd. II, p. 785. 
