Xii. INTRODUCTION. 



from St. Leonards to Fairlight, there are cliffs. The coast 

 is generally beach, bordered by long ridges of shingle or loose 

 stones thrown up by the waves. The line of shingle between 

 Worthing and Shoreham is very strongly marked ; there 

 Trifolium >stellatum is well established, and Vicia lutea 

 occurs with other rare species. Owing to the encroachments 

 of the sea, however, many well-known localities for plants, 

 as notably, Pilsey Island, are fast disappearing, and the 

 coast line at Bognor, Brighton, Newhaven, and elsewhere, is 

 undergoing considerable change. 



BOTANICAL DISTRICTS. 



Watson in his Topographical Botany defines the county 

 as the E. Channel sub-province, and separates it into W. 

 and E. Sussex by a line traced along the high road from 

 Brighton to Cuckfield, thence by Crawley to the border of 

 Surrey. The botanical districts here adopted are founded on 

 the river basins. With some slight modifications the 

 boundaries are the same as those traced by Mr. Hemsley, 

 which were carefully considered. They are as follows: 



I. WEST ROTHER. This district comprises the western- 

 most part of the County, bounded to the E. by a stream 

 from the Surrey border, which flows by Shillinglee, Kirdford 

 and Wisborough Green into the Arun, thence along the W. 

 bank of the Arun to the sea. It is drained, N. of the Downs, 

 by the West Rother, a tributary of the Arun which it joins 

 near Pulborough, and S. into the Channel by two 

 independent streams, the Ems and the Lavant. This portion 

 of the county has been well explored during the last fourteen 

 years by the Members of the Chichester and W. Sussex 

 Natural History Society, and many interesting additions 

 have been made to its Flora. 



II. ARUN. West Rother boundary to the W. Eastern 

 boundary, commencing at the Surrey border, through 

 Roughey Street, across St. Leonard's Forest, by Stone Lodge 

 and Colgate to Pease Pottage Gate, thence south to Hand- 

 cross, westward over Plummer's Plain to Monks' Gate, 

 across country to the junction of the railways near Plumtree 

 Cross, on to Bashurst and Ludwick, taking the main road to 

 Billingshurst, then leaving it again and crossing the railway 

 to the east of the station on to Coneyhurst, Broadford Green, 

 Chiltington, Thakeham, skirting Heath Common, through 



