90 



BULLETIN OF THE UNITED STATES FISH COMMISSION. 



fg- 



;^'. 



(O — I 



— »-. 



reddish-white color, i)roduced by the dev^op- 

 ment of adipose tissues and of the blood-ves- 

 sels, and not by the eggs filled with little glob- 

 ules of fat ; the genital aperture and thejissura 

 recto-vesicalis were open. 



In other eels of a length sometimes of 600 

 millimeters and more, I found the ovaries less 

 broad, with but little fat, and of a mucous and 

 almost glassy appearance, so that I could dis- 

 cern the so-called vesicles and germinative dots 

 {nuclei and nucleoli) ; the genital aperture and 

 the Jissura recto-vesicalis were closed. 



The ovaries of young eels, of the length of 

 about 500 millimeters, contained invariably but 

 little fat, and the eggs were without globules. 

 The gradual growth and enlargement of the 

 ovaries go on simultaneously with the opening 

 of the genital orifice. According to the quan- 

 tity of fat contained in the ovaries, they have a 

 mucous and glassy, or more or less opaque or 

 white, aj^pearance, or have small shining white 

 dots. From the end of March till October, I 

 found in the majority of eels which I examined, 

 measuring 600 to 700 millimeters in length, that 

 the ovaries were scarcely white, and that the 

 genital aperture was closed. The number of 

 eggs contained in both developed ovaries 

 reaches, according to my calculation, five mill- 

 ions. The larger eggs measured by me had a 

 diameter of one-fourth to one fifth millimeter, 

 while the eggs of an adult " grougo" {Conger) 

 had, according to my measurements, a diameter 

 of one-third of a millemeter, and those of the 

 " murena " {Murcena lielena) almost one mil- 

 limeter, which explains to me why the ovaries 

 of the two last-mentioned species of fish have 

 long since become known. 



In an eel measuring 590 millimeters, exam- 

 ined on the 6th July, the left ovary was en- 

 nai pouch, k. Fat on the ^Ib't tlrcly wautiug, aud replaced by a mass of fat. 



side. k' . SiniiUir fat roverinfj the 

 stomach. I. Fat ou the left side. 

 m. Stomach. n. Pylorus. o. 



liiver, turned up to show the inner 

 surface adhcriiiir to the cesophagus 

 and the .stomach. p. Gall-bald- 

 der. qq. Pectoral fiua. 



.1 







Fig. 5. Male eel {natural size) . 



a. Eightteisticle. b. Left testi- 

 cle, c. Right accessorj- part. d. 

 Left accessory part. e. Dividing 

 membrane. /. Deferent canal. 



g. Seminal pouch. h. Anal de- 



pression, i. Urinary bladder, cov- 

 ered to a great extent by the semi- 



Tlie S2)ermatic organs. — The position of these 

 organs (fig. 5), which are not ribbon-shaped 

 like the ovaries, but represent two longi- 



tudinal rows each with about fifty lobules 

 (fig. 6) of the width at most of three millimeters, and found only in 

 eels not more than 430 millimeters long, corresponds entirely with that 



