s8 t. b, rosseter on the genital organs of taenia 8inu0sa. 



Female Organs. 



Of the 115 to 120 species of avian tape- worms figured and de- 

 scribed by Krabbe in his Bidrag til Kundskab om Fuglenes 

 Baenddorme, 18G9, there are only four in which he foreshadows the 

 female genital organs — viz. T. microcantha, T. capito, T. villosa, 

 and T. shmosa — and even then in a very imperfect manner. If 

 we refer, in the case of T. sinuosa, to his sketch of these organs, 

 Tab. 7, fig. 153 (Fig. 5), we find merely the outline of certain 

 bodies, but nothing to indicate their individuality or functions. 

 I take them to represent the receptaculum seminis, paired ovaries, 

 and the shell and yelk glands. An undulating filiform streak is 

 seen passing dorsally of the vesicula seminalis, but there is 

 nothing to lead us to infer that it has any connection with 

 or plays any part structurally in the genital apparatus ; yet, 

 on close examination, we find that the contra is the case, and 

 that it does play a most important part and is an essential 

 portion of the female genital organs. In fairness to Krabbe it 

 must be admitted that these organs, however obscurely sketched 

 and unexplained by him, are to some extent accurately placed 

 in the outline of the sketched segment. 



In this species the female genital pore (Fig. 1, h) is quite distinct 

 from that of the male. It is situated in the same plane, dorsally, 

 but not on the lateral border. Its position is in the median line, 

 0'1G3 mm. from the lateral border. Thus it is some distance down 

 the segment, and it is instructive to note the manner in which the 

 whip-like cirrus, when exserted from the male pore for the purpose 

 of coition, glides from the lateral border down the segment to the 

 female genital pore. The vulva has a diameter of "026 mm. The 

 vagina is diaphanous and smooth both externally and internally. 

 The vaginal canal (Fig. 1, i) — which the thin undulating line 

 drawn by Krabbe across the vesicula seminalis in his sketch of 

 the genital organs evidentally is meant to represent, although 

 not described by him as such — runs obliquely, not undulatingly, 

 dorsally over the vesicula seminalis far up under the lappet of 

 the preceding segment, and is thus very much obscured and 

 •difficult to trace. It is then suddenly diverted, and returns 



