CLEANSING OF THE LITTORAL BY THE LUGWORM. 29 



are freely exposed. On the other hand, similar diffusion is infinitely 

 less rapid under water and indeed, the gases of putrefaction are 

 in sand and mud virtually closely confined. Again, decomposing 

 matter in the marine " soil " is without the slow-decaying fibrous 

 matter so common in earth. Water plants do not require woody fibre, 

 and they accordingly offer no resistance to decay. There is also 

 probably more decaying animal matter in sea " soil " than in earth. 

 The full value of the cleansing operations of the lug- worm is 

 not easily to be assessed. Without this humble worker, the littoral 

 would in many places become a veritable cesspool, calling for costly 

 human intervention, at least at those spots we dub as seaside health 

 resorts. Left alone, the wrack or seaweed cast up by storms would 

 putrefy, and whenever the thin covering layer of mud or sand were 

 removed, noisome gases in horrid volume would arise to vitiate the 

 erstwhile pleasant sea breeze. I do not draw a fancy picture. A few 

 weeks ago, on a tramp along the west coast of our little island, 

 searching for stray items geological, I tried to explore a little bay, 

 perhaps the most used of any in the island by farmers during the 

 wracking season, at that time in full swing. I write " tried to explore "' 

 advisedly, for the stench that rose from the bay was more than my 

 nostrils were prepared to end are. I stayed just long enough to 

 discover that the odours arose from the decay ofFucus and Laminaria 

 dropped by the carts as they returned up the slip way, from off the 

 shore. Some weed lay in forgotten corners above high water mark, 

 but the main body of the stench arose from the pebbles, gravel, sand 

 and pools. A greyish black slime enveloped and contaminated every- 

 thing beneath foot. Landlocked as the little bay is, the air hung 

 dense and heavy as that of a charnel house. One cannot exaggerate, 

 strange as it may seem. In this instance, the accumulation on the 

 beach of decomposable matter is too rapid for the lug worm to 

 contend with. 



While arguing the value of the cleansing of the littoral by this 

 worm, I do not, however, wish to convey the idea that finally the whole 

 of the decomposable matter is eliminated — only the bulk is removed. 

 A certain residue is left, explainable by reason of the worm 

 finding starvation conditions present, when the organic matter is 

 decreased to a definite point ; that reached, the worm removes to 

 where more food matter is present mingled with sand and mud. 

 Thus in a growing deposit, the progress of the lug-worm will be 

 upwards. As the deeper layers are exhausted of their carbonaceous 

 food supply, so the lug-worm gradually ceases to burrow down into 

 these and if new layers are all the while being added at the top, so 

 the dense black band which denotes the maximum presence of 

 unexhausted organic decay does not remain stationary or spread 



