REPORT OF COMMISSIONER OF FISH AND FISHERIES. [110] 



the cirrus. From this point it can be traced towards the median line 

 after having made a slight bend forward at the base of the cirrus bulb. 

 It then leads to the ovaries, at the anterior end of which it enlarges ab 

 ruptly and is joined to a much smaller tube, which continues in a very 

 sinuous course to the base of the cleft between the two lobes of the 

 ovary. A second small and very much folded tube, evidently the vas 

 deferens, enters the inner end of the cirrus bulb at its anterior angle. 

 From that point it can be traced forward a short distance, then back 

 along the median line, where it lies in dense folds or plaits, nearly to 

 the anterior edge of the ovary, where its course becomes somewhat 

 doubtful. A third large, straight tube with thick granular walls lies 

 along the median line from about the anterior third to a point a little in 

 front of the ovaries ; there it becomes abruptly enlarged, rounded, or 

 pyriform and is joined by a small duct. This duct is much folded or 

 plaited, lies between the lobes of the ovary, but extends a little way in 

 front of the ovaries to enter the pyriform termination of the straight 

 median duct. In some segments a round, lateral aperture was observed 

 at a point which corresponds to the anterior termination of the median 

 duct. In segments with ripe ova the region along the median line be- 

 comes distended with ova, which may be seen, in some at least, issuing 

 from the lateral aperture. The ova, in some of the sections stained 

 with carmine, are of a light amber color, oval, much collapsed, about 

 .05 mm in length and .O.I 1 " 111 in breadth. In other sections there were a 

 few ova which were apparently not yet provided with shells. They 

 were shorter oval than the mature ova, about .035 mm and .OJ4 mm in their 

 two diameters, and their granular contents deeply stained. The central 

 mass of ova in mature segments appears as a dark colored spot in alco- 

 holic specimens, sometimes likewise in living specimens. 



In stained sections the ovary was seen to be composed of polygonal, 

 nucleated cells, about .OOS nim in diameter. The nuclei were about 

 OO-miu j n diameter. Flat nucleated cells, somewhat smaller than the 

 cells of the ovary were found in the walls of the convoluted tube which 

 lies between the two lobes of the ovary. In sections of some of the 

 segments the nests of nuclei, which constitute the tcstes, were seen to 

 be breaking up into fine fibrilhie, presumably spermatozoa. This phe- 

 nomenon was best seen in segments which had but few or no ova. In 

 sections of segments which contained many ova there were large spaces 

 from which the nuclear aggregations of the testes had disappeared, leav- 

 ing a net-work of connective tissue. In the strands of this net-work 

 there are occasional minute fusiform nucleated cells. 



The walls of the mature segments, even those which are crowded with 

 ova, are plentifully supplied with both longitudinal and transverse 

 muscular fibers. These are pretty evenly distributed. The fact that 

 the muscular tissues do not soon degenerate is also shown by the long 

 continued vitality of the free proglottides. They continue active after 

 lying in sea water for several hours. It is probable that they continue 

 to grow for some time after becoming free from the strobile. 



