18 



conspicuous migration, except those which were caught on the York- 

 shire coast, and liberated on the Lincolnshire coast. Of these, both 

 males and females exhibited a strong tendency to return to the 

 original place of capture. Experiments, accidental and otherwise, 

 have been cited before which indicate that crabs have a homing 

 tendency, but the removal from one district into another intro- 

 duces a complication which at present it is not necessary to discuss. 

 If the experiments with reference to such crabs as were marked and 

 liberated at the place of capture are to be taken as conclusive, then 

 it appears that at or about the Wash the conditions undergo a change. 

 This is very probably the case, and more than likely is associated 

 with a hydrographical change. 



But more experiments are wanted. It is greatly to be desired 

 that an arrangement should be entered into for the marking and 

 liberating of a given number of crabs in the same or corresponding 

 seasons in the same year in as many districts as possible, with a 

 view to stating still more accurately a migration which is of such 

 biological and economic interest and importance. This should be 

 followed by similar experiments with reference to lobsters and 

 Norway lobsters. 



