Miscellaneous, 305 



little further forward, and terminates not quite so far back as that 

 of the left side, as is also the case with the ovaries. Both have at 

 their })osterior part a sort of prolongation (prt?-s recurrens), which 

 turns forward. Their hyaline aspect and their dimensions {^ve 

 them a great resemblance to the incompletely developed ovaries ; 

 but with a little attention it is seen that they have not the same 

 structure as the female organs, but form two simple longitudinal 

 series of lobules of regular form. Of these lobules there are about 

 48-50 in each testis ; they are compressed and shorter at their base 

 than at their free margin, which is broadly rounded, so that they 

 slightly cover each other. The ovaries are suspended from simple 

 ribbons formed by the peritoneum, whilst each of the testes adheres 

 to the walls of a longitudinal canal (the deferent duct). Each 

 canal terminates caically in front, and ends posteriorly in a triangular 

 sac (bursa semiualis) applied against the lateral walls of the urinary 

 bladder. The sac of one side is in communication with that of the 

 other by a transverse fissure (Jlssura recto-vesiccdis) which occurs 

 between the rectum and the neck of the urinary bladder. This 

 fissure also' leads from the two sacs into a pit (fovea recto-vesicalis) 

 which is continued into the genital pore. The genital pore itself 

 does not open directly outwards, but into the urethra. 



In the female there are neither canals nor sacs ; but the genital 

 pore also opens into the urethra. 



The sti'oma of the testis is much more resistant than that of the 

 ovary. Each lobe is formed of compartments about 0*05 millim. in 

 diameter, filled with isolated nuclei, aggregations of nuclei, and cells. 



The principal arguments which the author brings forward in 

 favour of his new intei-pretation of the reproductive apparatus of the 

 eels are as follows : — 



1. The organs which he regards as testes occupy the same rela- 

 tive position as the ovaries, but differ from the latter in form and 

 structure, 



2. The ducts which are in close connexion with them, and open 

 into the genital pore, cannot be any thing but the deferent ducts and 

 the vesicida; seminahs. 



3. The ducts, vesicuhp., and the genital pore open in proportion as 

 the testes are developed — a course of things which is the same as 

 that observed with regard to the female genital pore relatively to the 

 development of the ovaries. 



4. The lobate organs resemble, especially in structure, the testes 

 of the fishes allied to the eels. 



5. The eels which possess these organs are destitute of any other 

 formation that could be regarded as a reproductive organ 



This collection of facts appears quite conclusive. It now only 

 remains to discover the spermatozoids, which M. Syrski has not been 

 able to find in the small eels. This gap in the evidence is of con- 

 siderable importance ; and it is to be hoped that it may soon be 

 filled. — Sitzunrfsber. der Akad. der tviss. in Wien, Math.-naturw. 

 Classe, Band Ixix. April 1874 ; Bibl. Cniv. February 15, 1875, 

 p. 163. 



