REPRODUCTION AND DEVELOPMENT OF THE CONGER. 19 



sidering tliat iu many animals the male is smaller than the female, 

 he began to look for male eels among the smaller specimens. In 

 the second specimen he examined, which was 40 cm. (16 inches) in 

 length, he discovered the organs which he identified as testes. His 

 conclusion as to their nature has been confirmed by all subsequent 

 inquirers, although no one has yet found these organs in the ripe 

 condition, and thus brought the final evidence of demonstrating the 

 ripe spermatozoa of the eel. 



The largest male eel observed by Syrski was 43 cm. (17 inches) 

 in length. But Dr. L. Jacoby, who investigated the eel both at 

 Trieste and Comacchio after Syrski, in 1877, found males as long 

 as 48 cm. (18-^ inches) and as small as 24 cm. (9^% inches) in length. 

 The female eels reach a length, according to Jacoby, of one metre 

 (39 inches) and the thickness of a man's arm, but the majority of 

 adult females which migrate in autumn to the sea are not longer 

 than 70 cm. (27^ inches). Therefore if Hermes' specimen of the 

 male conger is of the average size of the male in that species, then 

 there is a much greater difference in size between the sexes in the 

 conger than in the eel. The male conger discovered by Hermes 

 was 2 feet 5-| inches long, while adult females are 5 to 7 or even 8 

 feet in length. The largest male eel recorded by Jacoby was 1 foot 

 7i inches long, while adult females are only 2 feet 4 inches to 3 feet 

 3 inches long. 



Brock, in his account of the researches he made at Naples, does 

 not include any discussion of the relative sizes of the two sexes. 

 Of the conger he merely says that he examined forty-five specimens, 

 of which the males and females were about equal in number. He 

 states that he obtained only one male which was perfectly ripe, and 

 that he got this in the middle of November. The size of this 

 specimen he neglects to mention. Of the female sex Brock describes 

 no ovaries far advanced in development, and here also he neglects 

 to mention the size of the specimens which he examined. Of the 

 common eel Brock only states that out of ninety specimens of 35 

 cm. (14 inches) in length and under which he examined, seventy-nine 

 or 88 per cent., were males, and among those of 35 to 40 cm. (14 

 to 16 inches) in length six were males. 



II. History of my own Observations. 



I have now to record the observations and experiments on the 

 conger which I have made at the Plymouth Laboratory from 

 November 7th, 1887, up to the end of the year 1890. I find that 

 my notes on the conger in No. 2 old series of this Journal, although 



