On the Strength and Development of the Grain of 
Wheat (Triticum vulgare). 
BY 
W. E. BRENCHLEY, B.Sc. 
Rothamsted Laboratory. (Lawes Agricultural Trust.) 
With Plates VIII and IX, and five Figures in the Text. 
T HIS investigation on the wheat grain was originally started in 1906 
with the idea of approaching the question of the c strength ’ of wheat 
from a biological standpoint. This term ‘strength’ is one that is by no means 
easy to define exactly. As is well known, the flours obtained from different 
species of wheat grown in different localities vary very much in the value 
they have for bread-making. One flour will produce what the baker calls 
a ‘ well- piled ’ loaf, of good shape, size, and texture ; another may work up 
into an equally large loaf from the same amount of flour, but of a very bad 
shape, while yet a third may yield a loaf bad or indifferent both in shape 
and size, and close and heavy in texture. These differences are all said to 
be due to the varying 1 strength ’ of the wheat flour. Authorities differ very 
much in the way they define this term (1, 2), but perhaps the best working 
definition to take at the present time, when the matter is so much debated, 
is that given by Biffen ( 3 ), that ‘ strength is the capacity of the wheat to 
produce a large, well-piled loaf’. 
Of recent years a great deal of work has been done on the consideration 
of this point, all more or less from the chemical side, the latest contribution 
being that of Wood ( 4 ), who maintains that there are at least two factors 
concerned with strength, i. e. the ratio of soluble salts to total proteid, 
governing the shape of the loaf, and also the sugars and nitrogen-free 
extract of the flour, controlling the size of the loaf. 
Since strength had also been correlated with the date of cutting and 
the character of the season, an attempt was begun at Rothamsted in the 
latter part of 1906 to find out whether this varying strength is in any way 
associated with cytological differences in the wheat grain during the process 
of ripening, and also whether the diverse manuring of soil in the same 
locality or the variety of wheat play any part in causing such differences, if 
they exist. 
[Annals of Botany, Vol. XXIII. No. LXXXIX. January, 1909.] 
