278 REPORT—1905. 
growth of the fungus mycelium. The subject is certainly one which 
promises to yield results of value in practice, and calls for more extended 
and exact observation. 
The importance of research on the particular function of the various 
constituents of the crop lies in the fact that it is only by the posses- 
sion of such knowledge we may possibly influence in desired directions 
the quality of our crops. With the effect of manuring upon the yield of 
most of our crops we are now familiar, but the question of ‘ quality,’ 
almost as important as that of yield, forms a more difficult problem. 
One particular example may be cited, that of wheat, because of late 
years it has been a subject of investigation in most wheat-producing 
countries. That quality of wheat which is of special commercial import- 
ance is its so-called ‘strength,’ the capacity of yielding flour of such a 
consistency in the state of dough as will retain the gases produced in 
fermentation with the formation of a tall, well-piled loaf. This property 
of ‘strength’ is usually found in a hard horny and translucent grain, the 
soft, mealy-looking wheats being as a rule ‘weak.’ Again, the strong 
wheats usually originate from districts like the Hungarian plain, the 
North-West of America, and South Russia, countries characterised by a 
typical Continental climate, cold and dry in the winter, with rains in the 
late spring and early summer, and a gradually increasing dryness and 
temperature up to the time of harvest. The wheats grown under the 
opposite conditions of a winter rainfall and a dry summer, as on the 
Pacific slope of North America, or an evenly distributed rainfall as in 
England or France, are on the whole weak. The differences in this 
quality are considerable when measured commercially ; for example, in most 
seasons the best Manitoban wheat will be worth 20 to 25 per cent. more 
than a corresponding grade of English wheat on the London market. The 
source of strength lies among the nitrogenous constituents of the wheat 
flour : it can be measured roughly either by determining the proportion of 
nitrogen in the flour, or by the old process of washing away the starch 
and leaving the gluten. Neither process agrees exactly with baking 
tests, nor do any of the more recent attempts to differentiate the wheat 
proteids by their solubility in various media, as, for example, the deter- 
mination of the so-called gliadin glutenin ratio. In fact in the present 
state of our knowledge of the possibilities of identifying and separating 
the proteids in a pure state, there is little likelihood of being able to make 
out the subtle differences of chemical composition which result in the 
varying quality of the wheat proteid mass. For example, the relative 
strength of different varieties of wheat grown under similar conditions 
will follow the order in which the wheats are placed by their con- 
tent in nitrogen; yet if, as at Rothamsted, an increased nitrogen 
content in the wheat is brought about by excessive nitrogenous 
mavuring, the product is actually considerably weaker than wheat 
on the other plots grown under more normal conditions. The manuring, 
while increasing the nitrogenous matter of the wheat, has probably 
introduced a new factor in the shape of a more prolonged develop- 
ment resulting in the lack of those final changes in the nature of the 
wheat proteids which make for strength. This seems to be indicated 
by the fact that on storage this particular abnormal wheat gradually 
increases in strength up to the normal, though never to the degree that 
would be indicated by its nitrogen content. But though the chemical 
methods of estimating the strength of wheat have as yet proved incon- 
