218 HOW CROPS GROW. 
other single period, viz.: 28°], A similar statement is 
true of phosphoric acid. It is obvious that Bretschnei- 
der’s crop was taking up fixed matters much more vigor- 
ously in its last stages of growth, than were Arendt’s 
plants. As to potash we observe that its accumulation 
ceased in the 4th period in both cases. 
It is, on the whole, plain that we cannot safely draw from 
these interesting researches any very definite conclusions 
as to the rate and progress of assimilation and growth in 
the oat plant, beyond what have been already pointed out. 
C.—Translocation of substances in the Plant,—The 
translocation of certain matters from one part of the plant 
to another is revealed by the analyses of Arendt, and 
since such changes are of interest from a physiological 
point of view, we may recount them here briefly. 
It has been mentioned already that the growth of the 
stem, leaves, and ear, of the oat plant in its Jater stages 
probably takes place to a great degree at the expense of 
the roots. It is also probable that a transfer of amyloids, 
and certain that one of albuminoids, goes on from the 
leaves through the stem into the ear. 
Silica appears not to be subject to any change of posi- 
tion after it has once been fixed by the plant. Chlorine 
likewise reveals no noticeable mobility. 
On the other hand phosphoric acid passes rapidly from 
the leaves and stem towards or into the fruit in the earlier 
as well as in the later stages of growth, as shown by the 
following figures : 
1,000 plants contained in the various periods, quantities 
(grams) of phosphoric acid as follows: 
ist Period. 2d Period. 30 Period. th Period. bth Period. 
83 lower joints of stem 0.47 0.20 0.21 0.20 0.19 
2middle ‘“ fe — 0.39 1.14 0.46 0.18 
Upper joint ae _ 0.66 1.73 0.31 0,39 
3 lower leaves “ 1.05 0.70 0.69 0.51 0.35 
2upperleaves ‘“* 1.7% 1.67 1.18 0.74 0.59 
Ear = 2,36 5.36 10.67 12.52 
