Mussel Colonies and Mud-heaps. 



205 



same. In this get included gravel, broken shells, barnacles, 

 sea-weeds, hydroids, &c., and frequently diminutive mussels 

 themselves. These entrapped, the latter grow and nourish, 

 and soon arises a colony of all sexes and ages. But the detritus 

 heaps altogether a rough sieve, no wonder mud collects 

 though in some senses deleterious, say near or among oyster 

 beds, yet are not without a benefit, for they foster and give 

 protection to a vast colonial life of all kinds of the lower 

 creatures many microscopic, fit food for the mussels and oysters 

 themselves. Mobius (Z,c.) has well shown the importance of 

 such social communities, and this has been emphasised by 

 others, and can be witnessed daily on our shores. The net 

 result is that the congregation of the infinitesimal and larger 

 sized fauna is of immense importance to the fisheries at large 

 as fish and shell-fish food, &c. 



FIG. 23. 



VIEW OF COCKLE BEACH, LEIGH, AT LOW TIDE. 



Cockling craft in foreground, men with " yoke " and baskets (two 

 sorts), &c. In distance and to right are cockle sheds and cockle-shell 

 heaps, and beyond row of fishermen's dwellings. 



