71 MR. W. S. EOWNTREE OX THE 



Of Macrodon, lie says on page 513, " J'ai trouve a I'ouverture de corps, les deux sacs 

 ovariques enveloppes dans leurs replis peritoneaux, et adherant cliacun a la parol 

 abdominale"; but on page 515, "Quant aux organes genitaux, lis ont, comme nous 

 I'avons deja dit, la disposition de ceux des Truites." Tlie ovaries of the other 

 Characinids are not mentioned by Valenciennes. 



Sagemehl * states that he has satisfied himself that the ovaries in these fishes are closed 

 sacs, thus confirming Miiller's description. He does not say in what forms he has made 

 the observations. 



I have up to the present time examined the ovaries in the following 14 forms : 

 Alestes nurse, Tetragonopterus ahrmnis, Petersias Leopoldiamcs, Micralestes alius, Alestes 

 longipinnis, Micralestes Stormsi, Sydrocyon Forskalii, Sarcodaces odo'e, Auacyrtus 

 microlepiis, Curimatns Gllberti, Macrodon trahira, Erythrinus unitceniatus, Lebiasina 

 blmaculata, Pyrrhulina semifasciata. In some cases, it is true, the condition of the 

 specimen was not such as to justify any statement about the ovaries, owing to the 

 disappearance of the membranous parts. In other cases, however, the membranes were 

 intact, and I was able to satisfy myself, by the use of the seeker and of the blowpipe 

 under water, that no communication existed between the ovarian sacs and the general 

 body-cavity; the sacs, through the medium of their membranous continuations, opening 

 directly upon the exterior by a common jjost-anal orifice. In all, the ovaries of the two 

 sides were equally developed, arising at the level of the anterior chamber of the 

 air-bladder. 



Nevertheless, it has seemed to me that two diff"erent ovarian conditions are dis- 

 tinguishable amongst the Characinids above mentioned : Sarcodaces (PL 4. fig. 29) may be 

 regarded as typical of the one, and Alestes nurse (fig. 30) of the other; bvit the 

 difference is, I think, only a question of degree in the backward extension of the 

 ovigerous tissue, and the reciprocally developed forward extension of the oviducal 

 membranes. In Sarcodaces the ripe ovaries extend back to just behind the level of the 

 anus, where they become closely approximated, but are not confiuent. Their membranes 

 there continue as a single, very short common duct to the exterior. Each ovary has the 

 appearance of being, as it were, slung by its membranes, which invest it completely, 

 except on the dorsal side, where a spaca or canal runs witliout interrujjtion to the 

 external opening. 



Similar conditions appear to obtain in Macrodon. Of the other Erythrinoids I can 

 speak with less confidence, but I believe their ovaries to have the relations just 

 described. 



In Alestes and Hydrocijon, on the other hand, according to my observations, the 

 ovaries fall distinctly short of the anus, so that the common oviducal space enclosed 

 by the backward continuation of their membranes is of considerable extent, instead 

 of being exceedingly small as in Sarcodaces. 



The two conditions I regard as being modifications in difl^erent degrees of the same 

 ovarian type. Although differing considerably at first sight, they agree absolutely 



* Sagemehl, '-Das Cranium der Characinidcii," p. 115. 



