VEGETATION OF BLAKENEY POINT. 51 



other species. If a plant be uprooted, the lower leaves of the 

 rosette immediately curl round towards the root, so that the 

 plant assumes a ball-like form, shewing that by the increased 

 growth of the upper surface of the leaves as compared with the 

 lower they are as it were " sprung " on to the soil beneath. 



All the species, except Convolvulus, which have the rosette 

 habit pass the winter in that condition. In Silene the leaves 

 remain through the winter, but the following year's growth is 

 continued by hibernating buds usually subterranean in position. 

 In Arenaria peploides all the leaves die back, buds similar to 

 those of Silene forming the foliage of the next season. In 

 Carex arenaria the leaves wither except at their bases, which 

 persist as a protection around the new leaf bud. 



Psamma, Arenaria, and Convolvulus Soldanella, which all 

 possess extensive rhizomes in the dune substance, shew modifi- 

 cations of the growing apex. In the first two the outer leaves 

 combine to form a tapering apex ending in a hard point, and 

 thus eminently suited to sand penetration. In Convolvulus the 

 growing apex bears a leaf which is bent back so that the petiole 

 receives the pressure, as in many seedlings. 



Before leaving the dunes it should be said that the whole 

 system is riddled with the burrows of rabbits, which, when they 

 fall into disuse, give lodgment for plants that there find shelter 

 and possibly added moisture. Thus, Aspidium recorded above, 

 which shares with Epilobium hirsutum the distinction of being 

 the rarest plant on the area, is found as an isolated specimen 

 situated in a disused rabbit-hole. The rabbits also no doubt 

 profoundly affect the vegetation in other ways more directly, as 

 by their actual depredations and by their excrements acting as 

 manurial agencies. 

 IV. THE SALT MARSHES. 



The septation of the Salt Marshes at Blakeney into separate 

 portions by the lateral banks gives us a whole series of small 

 isolated marshes in different stages of colonisation (fig. l), the 

 ages of which are broadly relative to those of the hooks which 

 bound them. An exception to this generalisation is given by 

 the large intervals where hook formation has not proceeded 



