120 Brenchley. On the Strength and Develop 7 nent of 
of the starchy endosperm lying just underneath the aleurone layer were 
found to be stained more deeply yellow than the rest, thus indicating the 
presence of a larger quantity of protein. The manner and extent of infilling 
of starch were noted, with other details of cell contents and structure, but 
both the types showed similar phenomena. Altogether it seems that the 
various points in the history of development are quite parallel in both the 
strong and weak wheats, and, after due consideration, the conclusion was 
arrived at that no cytological differences exist under these circumstances 
which can in any way afitect the strength of the grain —at least, no differences 
that can be observed by the methods used. The information gained as to 
the developmental history of the wheat grain will be treated fully in the 
latter part of this paper 
(2) As previously stated, Square Head’s Master is an example of 
a typically weak English wheat, even under the most favourable circum- 
stances, but largely grown because of its good yielding properties. 
The crop from the unmanured Plot 3 yields flour of a practically normal 
strength for the variety ( 5 ), which in 1902 was awarded a £ baker’s mark’ of 
42 for its bread-making capacity. The flour from Plot 10, however, with its 
very heavy nitrogenous manuring, behaves most abnormally in the bake- 
house. Although the grain looks strong, and contains a large percentage 
of nitrogen, as is shown by analyses, yet the flour proves to be excessively 
weak when tested just after harvesting, only receiving a nominal baker’s 
mark of 1, indicating that it is hardly possible to make bread from it at all. 
A curious and unaccountable change occurs as time goes on, as flour from 
the same wheat, when ground and tested again by baking about nine months 
later, proves to be quite as strong as the ordinary wheat from the Rotham- 
sted Fields (6), but this improvement with age only occurs in the wheat 
from this one particular plot. 
Again, an examination of numerous preparations carried on in the same 
way as in the elucidation of the first problem failed to reveal any cytological 
differences in the structure of the two sets of grains — though the material 
obtained from Plot 10 seemed to be a trifle less advanced than that from 
Plot 3, date for date, as the heavy nitrogenous manuring has a tendency to 
prolong the growing period, and so to slightly delay the progress of 
maturation. 
(3) Examination of grains of the same variety cut ‘ green ’ and £ dead 
ripe ’ showed certain cytological differences between them. When the grain 
begins to ripen, changing colour from green to brown, the nuclei in the 
amyliferous cells of the endosperm are perfect and complete, but as ripening 
proceeds these nuclei become much disorganized, owing to the pressure 
exerted by the increasing amount of starch in the cells, and also to the 
desiccation which goes on as maturation proceeds. With this exception the 
cytological structure does not seem to undergo any change, and it is hardly 
