AS AN INDEX OF AGE. 



103 



Note. — The ages thus determined agree with Fulton's results. According to Fulton, 

 the majority of Cod proljably hatch about the end of March and early part of April, and 

 this may be taken as the ]ieriod from which to date the average age of the season's brood, 

 and Haddock 8^ to 11^ inches long are 1 year and 5 months in September. 



The Scales of Eels. 



This paper commenced with the scales of the eel, and towards my 

 conclusion I must again refer to them. 



I have recently obtained eels from the Isle of May, Firth of Forth, 

 in order to examine their scales to see if by this means I could throw 

 any light on their interesting life-history. I endeavoured to obtain 

 eels from the lighthouse-keeper of the isle during the past winter 

 (1902-1903), but was informed hj him that they were never seen 

 there during winter. He thought they must bury themselves in the 

 mud at the bottom of the loch during winter- time, and it seems 

 probable that at this season they indulge in a winter sleep. In the 

 following August, however, the lighthouse-keeper was kind enough 

 to send me three eels, measuring 28, 33, and 35 inches respectively. 

 The eels of the Isle of May liave previously attracted the attention 

 of the biologist on account of their supposed history. They were 

 supposed to have been introduced there by the monks some centuries 

 ago, and to have lived in the land-locked loch on the isle since that 

 time. It had been held for sometime that eels could only breed in 

 salt water, and that those eels prevented from reaching salt water by 

 their land-locked habitat were tlie identical eels brought over by the 



