420 Salisbury . — The Soils of Blakeney Point : A Study of Soil 
tide.) Presumably, therefore, the effect is even greater in the Suaeda zone. 
In addition to the enhanced leaching effect which the higher level brings 
about, the less frequent and shorter duration of inundation increases the 
probability of the rainfall being efficacious. The views here expressed fully 
accord with those of R. H. Yapp and D. and O. T. Jones, whose study of the 
Dovey marshes led them to state that ‘ the vertical distribution of salt marsh 
plants . . . depends largely on the frequency and duration of the periods of 
submergence and emergence 
respectively ’ (Journ. Ecology, vol. v, 
p. IOO, 
1917). 
$ 
Chlorides. 
Decrease . 
Salicornietum 
A 
Before rain 5.7 
/o 
After rain 4-19-4.36 
% 
25 
Glyceria- Salicornia- Suaeda maritima 
„ 3 - 79 ~ 3* 2 7 
,, 2.50-2-08 
35 
Obione portulacoides 
„ 2.96-3.14 
» 0.37 
87 
Both the species in question occur high up on the shingle laterals 
where inundation is a rare phenomenon. As compared with plants similarly 
situated on the main beach, however, they are low in stature, and not 
infrequently of unhealthy appearance. Probably the low proportion of 
mineral salts and the acid reaction are here the limiting factors. 
Miss Halket found (Ann. Bot., vol. cxiii, 1915, pp. 143-54) that 
Glyceria mciritima grew best when the water contained no Tidman’s sea- 
salt, .S', ramosissima and Suaeda maritima grew best in a 1 per cent, 
solution, whilst 6'. Oliveri grown in varying concentrations of NaCl 
showed maximum growth in 2 per cent, solution. Since, in the last in- 
stance, sodium chloride was employed instead of the balanced solution 
furnished by sea-salt, it seems probable that maximum growth would have 
been exhibited in an even higher concentration of the latter. In any case 
it is significant that Salicornia Oliveri occupied the lowest zone at the 
Bouche d’Erquy, S', ramosissima an intermediate zone, and Glyceria the 
highest parts. 
The Statices, which are so well represented at Blakeney, present a series 
of species which, like the Salicornias, occupy successively higher zones 
of the marsh. Of these Statice humilis occupies the most frequently 
inundated marshes, and it may be for this reason is the only British species 
which fails to grow vigorously in ordinary garden soil. Suaeda fruticosa 
and Statice binervosa will, on the other hand, grow in garden soil with 
extreme luxuriance. 
Of the Salicornitum samples, those from the middle region of the 
Pelvetia marsh represent an old condition, whilst those from the Samphire 
marsh represent a very recent one. It will be noted that the proportion of 
organic material is greater in the older marsh. Similarly, whilst the 
relatively recent Obione zone of the Pelvetia marsh occupies a soil with 
from i*oi to 5-21 per cent, organic material, that of the old Obione marshes 
