Winifred E. Brenchley 15 



below the surface. The field is sometimes stocked with cattle and some- 

 times cut for hay, and the plants have opportunities of ripening their 

 seeds, as cattle do not eat the herbage down so seriously as sheep. This 

 helps to account for the comparatively large number of grasses and other 

 grassland ]ilaiits, the grasses being most abundant in the top four inches, 

 the abundance being in sharp contrast to the paucity of arable weed seeds. 

 The scarcity of arable plants may either be due to the length of time the 

 seeds have been buried or to the fact that comparatively few seeds were 

 left in the soil at the time of grassing down. This last suggestion is made 

 because (as will be seen later) the adjoining arable field alsf) yields remark- 

 ably few seeds, and the two fields were originally part of the same area. 

 Certainly the 12 arable seedlings from this field compare very badly with 

 the 75 plants obtained from a similar area in Geescroft. On the other 

 hand Barn Field has been definitely under grass since 1874, while Geescroft 

 was not finally thrown into the Park till 188.5, and the extra eleven years 

 would possibly account for the destruction of a large number of arable 

 seeds that may have been originally present in the soil. 



(3) Geescroft Field. 



This area was originally under arable cultivation, and was used for 

 various manurial experiments until 1878, but the land was very damp 

 and difficult to work and frequently became waterlogged. It was left 

 fallow for three years and in 1882 an unsuccessful attempt was made to 

 seed it down to grass. Barley and clover were then cropped but in 188-5 

 most of the field was thrown into the Park, so that the area has been under 

 grass since that date. Geescroft is a very long way from any ploughed 

 land and it is also protected to some extent by belts of trees, so that it is 

 most improbable that it has been infected with arable seeds by means of 

 wind carriage. It may safely be assumed that practically all the seedlings 

 of arable weeds that came up in this experiment were derived from seeds 

 that were lying dormant in 1885 or that were produced from plants that 

 ma\- have managed to survive for a year or two when the land was put 

 down to grass. Arable weed plants very soon succumb to the conditions 

 obtaining when land is under grass, and it is therefore unlikely that many 

 of the seeds are of later date than 1885. 



74 seedlings of typical arable weeds appeared in the soil of samples 

 aggregating one foot in area, the number of each species varying from 

 1 — 6, except in the case of Polygonum aviculare, of which 52 plants 

 appeared. These Polygonum seedlings occurred in every inch except the 

 first, the largest numbers appearing from six to nine inches down. The 



