SEVENTH DAY.] CONGER EEL. 199 



Their increase is not certainly known in any given 

 time; it must depend upon the quantity of their 

 food ; but it is probable they do not become of the 

 largest size, from the smallest, in one or even two 

 seasons ; but this, as well as many other particulars, 

 can only be ascertained by new observations and 

 experiments. Bloch states, that they grow slowly, and 

 mentions, that some had been kept in the same pond 

 for fifteen years. As very large eels, after having 

 migrated, never return to the river again, they must 

 (for it cannot be supposed that they all die imme- 

 diately in the sea) remain in salt water ; and there is 

 great probability, that they are then confounded with 

 the conger, which is found of different colours and 

 sizes from the smallest to the largest from a few 

 ounces to one hundred pounds in weight. The colour 

 of the conger is generally paler than that of the eel ; 

 but, in the Atlantic, it is said, that pale congers are 

 found on one side of the Wolf Bock, and dark ones 

 on the other. The conger has breathing tubes, which 

 are said not to be found in the other eel : but to 

 determine this would require a more minute examina- 

 tion than has yet been made. Both the conger and 

 common eel have fringes along the air bladder, which 

 are probably the ovaria; and Sir E. Home thinks 

 them hermaphrodite, and that the reproductive ves- 

 sels are close to the kidneys.* I hope this great 



* [The best and latest researches have proved that this opinion of Sir 



