272 
Amoehotaenia s2)henokles 
straight narrow tube with a diameter of 0-002 mm. It has a thin wall 
which stains intensely black with haematoxylin and is probably of a 
chitinous nature. 
Female Organs. 
With regard to the appearance of the female genital organs, Cohn 
states, “ In die sechsten Proglottis sind neben den gut entwickelten, 
wenn auch noch nicht reifen Hoden das Ovarium und der Dotterstock 
nur eben angelegt.” My own specimens do not confirm this statement. 
I have found unmistakable traces of a vagina and yolk-gland as 
early as the fourth segment, and possibly more careful staining would 
reveal them in preceding proglottides, Magelhaes having found the 
vagina in the third. Neither can the following statement be regarded 
as correct : “ Nachdem sie {i.e. the female genital organs) aber einmal 
im ll-12ten Ghede das Maximum der Entwicklung erreicht haben, 
verschvfinden sie mit einem Schlage, so das im 13ten Ghede, das bereits 
ganz mit dem Uterus geflillt ist von Ovarium und Dotterstock keine 
Spur mehr vorhanden ist.” 
The female genital organs persist as far as the 14th proglottis in 
which yolk-gland, ovary, and receptaculum semims can be seen quite 
distinctly. Posterior to this they disappear gradually, the yolk-gland 
being quite distinct in the 16th segment. The uterus which fills the 
13th segment according to Cohn is probably the ovary, which is there 
fully developed and filled with eggs so as to resemble a mature uterus : 
the uterus really is not properly developed until the 16th segment but 
remains overlaid by the ovary. 
The ovary (PI. XX, fig. 4, ov.) lies on the ventral side of the proglottis, 
a little to one side of the median line, and half-way between the anterior 
and posterior borders. It consists, at first, of two short wings connected 
by a long narrow isthmus, the wing nearest the genital pore being 
slightly the smaller. In the more posterior segments however, it in¬ 
creases considerably in width, beconung less rope-like, and curls con¬ 
siderably ; the isthmus often touches the anterior border of the proglottis 
while the ends reach the posterior border. It is while the ovary is in 
this condition that maturation of the eggs occurs. In the follovfing 
segments the ovary quickly disappears, no trace of it being found in 
the 16th. 
The yolk-gland {y.g.) also hes on the ventral side of the proglottis, 
and directly posterior to the isthmus of the ovary. It is a flat compact 
disc-shaped organ composed of a number of roughly spherical cells with 
