208 Agricultural Education and Forestry Exhibition , 1906. 
The Royal Agricultural Society lias repeatedly drawn atten- 
tion to the serious losses caused by warbled hides, and the 
exhibit was arranged at Derby with a view of bringing once 
more under the notice of farmers an evil which is largely 
preventable by the adoption of proper and well-concerted 
measures. 1 
Royal Agricultural Society of England. — No inconsiderable 
proportion of the Exhibition was devoted to the Society’s own 
scientific departments. The various publications of the Society, 
including books, pamphlets, leaflets, diagrams, &c., were again 
exhibited and sold. Similar exhibits to those of previous years 
were sent by the Society’s Botanical and Zoological depart- 
ments, the former including a new large diagram illustrating 
the results of experiments on the germination of farm seeds. 
These are described in the Report of the Consulting Botanist 
at page 257 of this Volume. 
The exhibits from the Society’s Woburn Experimental Station 
comprised the illustration of several series of experiments by 
plants growing in pots, a number of diagrams and photographs 
having reference to the field experiments, and also specimens 
of corn and grass from various experimental plots. 
Prominent among the pot cultures were those which 
showed how land, naturally poor in lime, could, after a 
period of continuous corn-growing and yearly manuring wdth 
ammonia salts, be rendered absolutely sterile for a crop of 
wheat or barley. The weed spurry ( Spergula ctrvensis ) was 
the only thing that would grow on this soil. By dressing the 
soil with lime the fertility could be restored ; but it was 
shown that with barley an application of 1 ton of lime to the 
acre was not enough to destroy the spurry and to neutralise 
the acidity produced in the soil. When, however, the acid 
soil was sterilised by boiling it thoroughly with water, the 
acid constituents were removed, the spurry weed would no 
longer grow, and lime, then applied, was effective in restoring 
a full crop. 
In another series of pot cultures the influence of lime and 
magnesia in varying relative proportions was shown. When 
the proportion of lime to magnesia in the soil was as 2:1, 
the wheat crop throve well ; when, however, lime and 
magnesia were present in about equal proportions the crop 
was considerably reduced ; and when magnesia was in excess 
of lime then the crop was almost a failure. This matter is, 
however, under further investigation, as the question Avould 
1 Journal R.A.S.E., Vol. 56, 1895, pp. lxxxi, lxxxii. See also Professor 
Penberthy’s article on “Parasites” in the current Volume, pp. 65-67. A leaflet 
on “ Warble Flies ” is issued free of charge by the Board of Agriculture 
and Fisheries, 4 Whitehall Place, S.W. 
