524 MR. J. B. LAWES, DR. GILBERT, AND DR. PUGH ON 
drawn. It would hardly be supposed that, under such circumstances, the process of 
cell-formation could go on. without the assimilation of free Nitrogen, provided any forces 
were exerted in the cell the tendency of which was to fix free Nitrogen in the organism 
of the plant. 
One fact, briefly alluded to above, we wish to call more special attention to, as afford- 
ing strong evidence of the absence of the power on the part of these cereal plants to 
appropriate free Nitrogen—namely, the very large development of the root, requiring 
but little Nitrogen compared with that of other parts. It was observed, in the expe- 
riments of 1857, that several of the cereal plants developed a large proportion of root ; 
but the danger of accident in analysis was such, that we hesitated to double the risk of 
losing the entire result by analysing the root and the portion of the plant above ground 
separately. They were, therefore, thoroughly mixed, and the mixture was carefully 
divided; so that, in case of accident, a duplicate was at our disposal, and in case of all 
going well, confirmatory evidence was obtained. So very marked, however, was the 
great development of root in the cereals of 1858, that, in several cases, it was analysed 
separately from the other parts of the plant. The remarkable result was obtained, that 
this great root-development was carried on (in two, at least, out of the three instances in 
question) with a consumption of an almost incredibly small amount of Nitrogen, as the 
figures given in the following Table will show :— 
Taste XIII. 
Dry Matter in Produce 
(at 100° C.), grammes. Nitrogen in Produce (grammes). pie a Per cent. 
Description of Plant. i — LN 
In Stems, In Total |) In Stems, | In Total Pee 
- 1858. &e. ies Biogis Produce. | Tn Roots. | Produce. | in Roots. | in Roots. 
| 
Wheat (1) ......... | 0°890 0°850 1-740 | 0:0039 | 0:0017 | | 0-0056 |; 48°85 30-36 
Barley (2) ......... 0-400 0-160 0-560 0°0027 | 0°0004 0:0031 28°57 12°90 
Oats (8) ssesaaa 0°798 0°350 1148 | 0°0040 | 0:0002  0-0042 30°49 4-76 
The large proportion of root and its small proportion of Nitrogen, as here exhibited, 
are equally remarkable. Whether this great power of the plant to develop root be due 
to the fact that the process of cell-formation in the root requires less of the nitrogenous 
protoplasmic compound, or to the fact that, floating in water as these roots generally 
were, that fluid facilitated the withdrawal of the nitrogenous constituents resulting from 
the decomposition of protoplasma from the old cells, to form new protoplasma for the 
more active cells, is a question which, though foreign to our present subject, is of con- 
siderable interest in a physiological point of view. The fact that the roots from the 
base of the stem penetrated the soil, giving off very few branches into it, but immedi- 
ately on reaching the water at the bottom of the pot exhibited such a remarkable deve- 
lopment (see Notes on taking up the Wheat Plants, Appendix, p. 560), is in favour 
of the inference that the water afforded the necessary conditions for the character of 
growth referred to. 
