247 
The Bouche d' Erquy in 1907. 
have been in full progress but for unforeseen mishaps. The annual 
halophytes should prove admirable material for such a purpose in 
view of the abundance of seed produced and its ready power of 
germination. Moreover, Salicornia does not appear to offer any 
insuperable obstacle to hybridising experiments. On the other 
hand, the conditions best calculated to bring out the differentiating 
colour-characters are not altogether easy to secure away from the 
salt-marsh. Some of these practical difficulties are on the way to 
solution; meanwhile it is proposed to carry out experimental 
cultures in a portion of a reclaimed meadow where, owing to 
percolation, halophilous conditions still prevail. Experiments of 
this kind on the marsh itself are precluded owing to liability of 
contamination by foreign seed brought by the tide. 
Cross-Pollination. 
Before leaving this part of the subject it may be mentioned 
that experiments commenced in 1906 and continued this year shew 
that a fairly wide dispersal of pollen-grains by the agency of wind 
is a normal occurrence on the marsh. The amount of pollen thus 
carried on a breezy day, taken in relation to the duration and 
distribution in time of the flowering periods of the various forms 
(e.g. 6'. Jierbacea, red and green forms ; 5. radicans) would account 
for a good deal of crossing, should the existence of hybrids be 
suspected on other grounds. Indeed, considering all the circum¬ 
stances, so far as they are known, the conditions for the natural 
production of hybrids on the Erquy marsh could hardly be more 
favourable. 
Marsh-Building. 
Another branch of work to which a good deal of attention was 
devoted this year was the process of marsh-development. 
Broadly speaking a salt-marsh represents one of the ways in 
which the waste products of the land are worked up once more into 
vegetation-bearing ground. The character of the Brittany coast 
favours the erosion of the rock, and the resulting particles finding 
their way on to the beach are blown above tide-level to form sand- 
dunes or they are carried up the “ Bouche ” by tidal currents. 
Moreover, the dune-spit which closes in the estuary has had a good 
deal of sand cut away during the last few years, so that there is an 
abundance of supplies of the raw materials for marsh-building 
