experiments, 1872 ; and the quantities represent the relative 

 proportion by weight in which each species was found in the 

 mixed produce of the plots. 



The mean produce of hay per acre per annum has ranged on 

 the different plots from about 23 cwts. without manure, to about 

 64 cwts. on the plot most heavily manured. 



The number of species found has generally been about 50 on 

 the unmanured plots, and has been reduced to an average of 

 only 20, and has sometimes been less, on the most heavily 

 manured plots. 



Species belonging to the order Graminacece have, on the 

 average, contributed about 62 per cent, of the weight of the 

 mixed herbage grown without manure, about 55 per cent, of 

 that grown by purely mineral manures (that is, without nitrogen), 

 and about 93 per cent, of that grown by the same mineral 

 manures with a large quantity of ammoniacal salts in addition. 



Species of the order Leguminosce have, on the average, con- 

 tributed about 8 per cent, of the produce without manure, 

 about 26 per cent, of that with purely mineral manures, and 

 less than O'Ol per cent, of that with the mixture of the mineral 

 manures and a large quantity of ammoniacal salts. 



Species belonging to various other orders have, on the average, 

 contributed about 30 per cent, of the produce without manure, 

 about 1 9 per cent, of that with purely mineral manures, and only 

 about 7 per cent, of that with the mixture of the mineral 

 manures and a large amount of ammoniacal salts. 



Not only the amount of produce, but the number and descrip- 

 tion of species developed, have varied very greatly between the 

 extremes here quoted, according to the particular character or 

 combination of manure employed, as is strikingly illustrated by 

 the arrangement of the specimens in the case. 



278. Specimens of Barley grown in Sweden, with 

 description, part of the collection of cereals arranged by 

 J. Eriksson* In progress. 



Published by Victor Petterson, Stockholm. 

 E. 58. 1889. 



279. Phykotheka Universalis. A collection of examples 

 of seaweeds. In progress. 



By Dr. F. HaucJc and Paul Richter, Leipsic. 

 E. 59. 1889. 



280. A series of mounted preparations and drawings 

 showing insects injurious to vegetation, damage caused 

 by them, and methods of extermination. Prepared for 

 the Science and Art Department by Miss E. Ormerod 

 and Prof. J. 0. Westwood. 



