244 TRANSJk.CTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



yearly gaining a small advance on the land to the 

 north-east, but are prevented from making greater 

 inroads by the growth of Ammophila arundinacea, 

 Carex arenaria, Salix repens, and a number of other 

 plants. During the raised -beach period the sea 

 encroached on the lower-lying land in this district 

 of Ayrshire to the extent of about 14 square miles ; 

 and such of this land as is not now occupied by 

 drifting sand is either laid down in permanent 

 pasture of a very poor quality, or, if cultivated, 

 consists of a very sandy soil which, as the farmers 

 forcibly put it, will " worry up any quantity of 

 manure." Large quantities of sea-weed are cast 

 ashore after a storm, and many hundred tons are 

 annually collected by the farmers for use as manure. 

 There are differences of opinion amongst farmers 

 as to its qualities as a fertiliser; but there can be 

 little doubt that if the farmers would first utilise it 

 as fuel, as is done in the Channel Islands, they 

 would find in the rich ashes an excellent manure 

 much superior to a great deal of the artificial 

 material which is supplied to them. The great bulk 

 of the sea-weed cast ashore consists of Laminaria, 

 Fucus, and Halidrys, as well as the marine flowering 

 plant Zostera. 



In early winter, at least 70 per cent, of the 

 Lamiyiaria digitata has a subconical hollow eaten 

 into the lower part of the stem by the little gastropod 

 Helcion pelluciduin, the stems having been broken 

 away just at this part; but much of the Laminaria 

 is also cast up with the roots entire, and bearing 

 with them stones of a considerable size as well as 

 quantities of gravel. It is probable, indeed, that 

 any stones and gravel existing on this shore may 

 have been brought hither by the sea-weeds, pre- 

 sumably from some old beach that was formed when 

 the land stood somewhat higher than at present. 

 The leaves of Zostera marina are often rolled together 

 into small wisp-like masses. To many of the sea- 

 weeds are attached various species of Polyzoa, and 



