THE COD FISHERIES NEAR THE LOFFODEN ISLANDS. 591 



poisonous threads extendiug iu all directions make tbem objects of terror 

 to all smaller animals, and cause even human beings to avoid them care- 

 fully, seemed so utterly inexplicable that I thought in the beginning these 

 fish must against their will have gotten into the power of the medusae. 

 This animal did, i)erhaps, exercise a magic i)ower over the poor young 

 fish similar to that of certain tropical snakes, which make little birds fly 

 right into their open jaws. But on closer observation I abandoned 

 this idea. These little fish were swimming about fearlessly between the 

 numberless threads of the medusa3 ; they were scared away by the least 

 noise, returning again after some time. There must consequently be 

 something which attracted the fish toward the medusae. Possibly they 

 sought shelter under their large disk against other fish. This explanation 

 seemed plausible, but was not entirely satisfactory. Careful observa- 

 tions have now convinced me that the young fish approach the me- 

 dusai chiefly for the purpose of catching the many small animals which 

 constitute the food of the medusce, and which it stupefies by its numer- 

 ous poisonous threads stretched out in all directions, finally towing them 

 up close to its disk. 



Although the young fish thus deprive the medusa of part of its legiti- 

 mate food, they at the same time render it a very important service 

 which fully compensates for the loss of food. The medusa is much 

 troubled by a parasite, a small crustacean (Eyperia), belonging to the 

 tribe of the amphipods, which — often in very large numbers — cling 

 firmly to the medusa by means of their sharp claws, and eat their way 

 deep into its jelly-like body. I invariably found some of these crusta- 

 ceans in the stomachs of the young codfish. 



This remarkable relation between the medusa and the young codfish 

 is not, however, entirely free from danger to the latter, although iu many 

 cases it affords a safe place of refuge from the persecutions of other fish. 

 By coming too near to the disk of the medusa the small fish may easily 

 get entangled in its poisonous threads and thus lose their life. I have 

 found a tolerably large young codfish which had met its death in this 

 manner. 



The following days I paid frequent visits to these inlets in order to 

 make further observations of the young codfish, and I found the local- 

 ity exceedingly favorable for my purpose. "Whenever the tide comes in 

 the current brings large masses of medusa) floating on the surface of the 

 water ; and when the water is very high they are often so closely piled 

 together that one cannot see the bottom, and I was always sure of find- 

 ing some young codfish under them. These, however, were now so quick 

 in their movements that I had to be very skillful in managing my purse-net 

 in order to catch them. In most cases they disappeared with lightning- 

 like rapidity as soon as they saw my i)urse-net, and 1 only succeeded 

 ^n catching them when they were so hidden under the medusae that they 

 could not notice the first movement of the purse-net. The largest 

 young codfish which I caught in this manner measured about 40 milli- 



