MODES OF FEEDING OF FISHES. 101 



upper side of the head of a Sole, the animal is still unable to find 

 it but continues to feel for it on the sand. There is however no 

 reason to suppose that the sight of these fishes is deficient. A 

 Rockling at Plymouth had already learnt to come out to be fed it 

 any one came near the tank, though it still did not i-ecognise a 

 worm swimming in the water. Particulars were given of the 

 various irideal mechanisms which occur among fishes. 



This investigation was undertaken at the instance of the Marine 

 Biological Association as a preliminary step towards improving the 

 supply of bait. The experience gained suggests that a bait for 

 the south coast, where Conger and Skate are chiefly caught, could 

 be made by extracting the flavour of Squid or Pilchard and com- 

 pounding it with a suitable ground-substance. Though few practical 

 experiments were made, it was found that an ethereal extract of 

 Nereis or Herring, for example, greatly attracted some of these 

 fishes. 



