8 7 
enclosing the Seeds of some of the Gramineae. 
Apparently this is due to the grain of Triticum and Secale not retaining 
the pales as a protective covering, as in the case of Hordeum and A vena, 
and consequently to the skins which compose the pericarp and spermoderm 
of the grain of Triticum and Secale being more exposed to accidental 
injury. 
Conclusion. 
This paper gives an account of the preliminary work of an investigation 
which is being continued, and although the results so far obtained suggest 
further discussion both from a botanical and a physico-chemical point of 
view, it appears desirable at present to await the results of experimental 
work which is proceeding. The following summary appears, however, to 
be justified: — 
1. The grain of Hordeum is enclosed within a semi-permeable or 
selective covering, which permits the passage of water and iodine to the 
interior of the grain, but which prevents the passage of sulphuric and 
hydrochloric acids, and all salts of metals at present examined, when they 
are in aqueous solution. 
2. The semi-permeable property of the covering of the grain of Hordeum 
is not due to the action of living protoplasm. 
3. The semi-permeable property of the covering of the grain of 
Hordeum is located in the spermoderm of the grain. 
4. The grain of Avena, Triticum , and Secale is enclosed in a semi- 
permeable covering apparently similar to that of the grain of Hordeum . 
School of Brewing, 
University of Birmingham. 
