|
| |
| May 15 | 7 weeks | 1 | 20.6 | 6.6 | 53.9 | 10.2 | 5.5 | 1.20 : 1 |
| | | 6 | 17.8 | 5.8 | 56.7 | 9.6 | 5.4 | 1.07 : 1 |
| June 18 | 12 weeks | 1 | 34.6 | 8.0 | 38.2 | 14.7 | 5.6 | 1.42 : 1 |
| | | 6 | 33.4 | 7.6 | 44.5 | 15.0 | 6.7 | 1.14 : 1 |
| July 16 | 16 weeks | 1 | 52.8 | 12.1 | 55.6 | 16.3 | 9.1 | 1.33 : 1 |
| | | 6 | 54.4 | 10.6 | 46.2 | 19.1 | 8.8 | 1.20 : 1 |
| Aug. 16 | 20 weeks | 1 | 66.8 | 9.2 | 49.1 | 17.0 | 8.3 | 1.10 : 1 |
| | | 6 | 65.0 | 9.8 | 49.8 | 19.1 | 9.4 | 1.04 : 1 |
| Sept. 3 | 22 weeks | 1 | 84.3 | 10.4 | 45.7 | 17.6 | 8.0 | 1.31 : 1 |
| | | 6 | 86.3 | 10.2 | 45.3 | 17.3 | 7.8 | 1.30 : 1 |
|_________|__________|_____|______|______|______|______|______|__________|

The variations exhibited by these numbers are significant. It is clear,
on the other hand, that the assimilation of the furfuroids does not vary
in any important way with variations in conditions of atmosphere and
soil nutrition. They are essentially _tissue_-constituents, and only at
the flowering period is there any accumulation of these compounds in the
alkali-soluble form. It has been previously shown (ibid. 27, 1061)
that the proportion of furfuroids in the straw-celluloses of the
paper-maker differs but little from that of the original straws. For the
isolation of the celluloses the straws are treated by a severe process
of alkaline hydrolysis, to which, therefore, the furfuroid groups offer
equal resistance with the normal hexose groups with which they are
associated in the complex.

The furfuroids of the cereal straws are therefore not pentosanes. They
are original products of assimilation, and not subject to secondary
changes after elaboration such as to alter either their constitution or
their relationship to the normal hexose groups of the tissue-complex.

(1) CONSTITUTION OF THE CEREAL CELLULOSES

(Chem. Soc. J. 1896, 804).

(2) THE CARBOHYDRATES OF BARLEY STRAW

(Chem. Soc. J. 1896, 1604).

(3) THE CARBOHYDRATES OF THE CEREAL

STRAWS (Chem. Soc. J. 1897, 1001).

(4) THE CARBOHYDRATES OF BARLEY STRAW

(Chem. Soc. J. 1898, 459).

C. F. CROSS, E. J. BEVAN, and CLAUD SMITH.

These are a series of investigations mainly devoted to establishing the
identity of the furfural-yielding group which