SEA-FISHERIES LABORATORY. 303 



in stormy weather the worms sink more deeply, and are, 

 of conrse, more difficult to obtain. 



Although lugworms have been so long used as bait, 

 and fishermen have searched the same areas of sand day 

 after day, there is usually no lack of them on most beaches. 

 Professor M'Intosh* suggests that they have " resisted the 

 attacks of man probably because a sufficient stock of ripe 

 examples and the very young are covered at all times by 

 the tide." It is certain that plenty of old ones are covered 

 by the tide, judging from the large specimens to be taken 

 at low spring tides. t The habits of young ones are 

 unknown, except those of the post-larval stages which are 

 pelagic. 



Arenicola produces enormous numbers of eggs, as is 

 seen from the condition of ripe females in the spring. + 

 In these the coelomic fluid contains many thousands of 

 full-sized ova.|| 



Unfortunately nothing is known about either the 

 oviposition or the early stages of development of the 

 common lugworm. We can only suggest, by inference 

 from the known facts of development of other species of 

 Arenicola, that the eggs are laid, probably entangled in 

 mucus, on or in the sand in shallow water, and the early 



* Eesources of the Sea, p. 14. 



t Reckoning only the specimens which are exposed at an ordinary 

 low tide their number is so great that the number removed at any one 

 time for bait really makes no appreciable difference. Take, for 

 example, the area from which the Musselburgh fishermen dig their 

 bait. For a distance of about a mile from East to West there is a zone 

 from one to two hundred yards wide immediately above ordinary low- 

 water mark in which the castings average twelve to fifteen per square 

 yard. This area would, therefore, contain from three to four million 

 worms, and the removal of a thousand per day would produce little 

 effect upon the enormous number of worms accessible even at ordinary 

 low tides. How far seawards the worms extend below ordinary low- 

 water mark it is impossible to say, but no doubt there are here very 

 substantial reserves. 



\ And also, in some localities, in late summer or autumn. 



|| There were about 80,000 ova (a rough estimate made by the 

 dilution method) in the coelomic fluid of one specimen examined. 



