The Shingle Beach as a Plant Habitat. 
79 
confidence that the same explanation holds here also, i.e., that the 
right-angled limbs of these hooks were produced at some remote 
period by heavy gales blowing from the west. 
So far as the majority of our English shingle spits are concerned, 
as a glance at our charts of a representative selection will show 
(Text-fig. 4), the tendency to hook-formation is concentrated at the 
distal extremity. In several of these banks concerning which 
historical records are available (c.g., Hurst Castle, Calshot 
Spit) there has been no advance for centuries, whilst at Blakeney, 
after a long period of advance, there has in the last fifty years been 
actual wasting at the tip. 
Fig. 4. Sketch maps of (1) the Hamstead Dover, (2) Hurst Castle, and 
(3) Northam shingle banks, showing hook-formation. Maps 1 and 3 have been 
reversed to facilitate comparison with 2. 
In view of this, the conclusion is almost irresistible that a shingle 
spit has quite definite, successive phases. There is the phase of 
youth in which growth is mainly in length ; and this is followed by 
