362 Smith : Botany at the British Association. 



represented by contributions on salt marshes of the Severn, and 

 on the woodlands of north-east Kent, The semi-popular lecture 

 by Professor Bower was a sketch, amplified by excellent 

 lantern slides, of the growth of sand dunes from their earliest 

 phases onwards, till they become the ' tees,' ' putting greens,' 

 ' bunkers,' and all that goes to make the sea-links so dear to the 

 keen golfer. 



On the Saturday an excursion took place, attended by over 

 sixty members, and led by Messrs. Bentley and Snelgrove. 

 The route was typical of Derbyshire, beginning with the Mill- 

 stone Grit escarpment Oakwoods at Grindleford, passing to 

 the Carboniferous Limestone dale at Eyam, and finishing 

 with a typical piece of dry Grit Moorland with Ling, Bilberry, 

 and Cowberry on the way to Hathersage. 



The Handbook, as far as Botany is concerned, was entirely 

 the work of members of the Yorkshire Naturalists' Union, 

 Mr. E. Snelgrove strikes a happy medium between descriptive 

 topography and details of plant species, and the photographs 

 by Mr. Bentley convey a very good idea of the types of vegeta- 

 tion. The Fungi by Mr. T. Gibbs, and the Algae and Dia- 

 tomaceae by Mr. M. H. Stiles, also give a good general summary 

 of what is known of these groups in the district. 



The work of another Section, that of Agriculture, also 

 included matter of botanical interest. The President, Mr. A. D. 

 Hall, sketched the progress of knowledge bearing on the food- 

 supply of plants, from its earliest stages through the ' chemical 

 period ' of potash, phosphates and nitrogen, to the more recent 

 ' biological period,' when the life in the soil is being demon- 

 strated to be such an important factor. Perhaps the most 

 striking contributions were those from Rothamsted, on the 

 great increase in soil-fertility, which has been traced when soil 

 is partially sterilised by heat or otherwise. There is strong 

 evidence to show that in the soil two opposing forces of micro- 

 organisms exist, one set assists in the preparation of available 

 plant food, the other set preys on these ; hence if the latter be 

 •destroyed, the useful organisms increase, and provide crop- 

 plants with greater supplies of food. Leeds smoke and its 

 influence on the growth of grass in the neighbourhood, provided 

 Dr. Crowther and Mr. Ruston of Leeds University with a 

 theme ; a series of observations and experiments confirm the 

 popular opinion that grasslands near grimy cities suffer directly 

 from the products of combustion of coal. 



Naturalist, 



