46 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
gonads were degenerated. The hooks of the cysticercoid completely 
agree in form and size with those of Taenia fasciata , which lives in the 
intestine of domesticated and wild geese. Cysticercoids have also been 
found in Ostracoda — in Cypris ovum and C. compressa ; as the infested 
animals lived for some time in captivity, the harmful influence of the 
parasite must be slight. These cysticercoids have hooks of the form and 
number of those of Taenia coronula, which has been found in the intestine 
of some species of Ducks. A new (third) species is now described from 
Gammarus pulex, but it is not yet known what its Vertebrate host is. 
Generative Apparatus of Taenia Echinococcus.* — Herr R. v. Er- 
langer gives a description of the generative apparatus of Taenia Echino- 
coccus. The female organs consist of the ovary, yolk-gland, shell-gland, 
and uterus, with their efferent ducts. All but the shell-gland open together 
into the atrium, which has a rounded or oval form, and consists of 
spindle-shaped cells. The yolk-gland is placed at the hinder end of the 
proglottis, and consist of two portions, one of which lies above the other. 
Each part is again divided into two lobes, and each lobe has an efferent 
duct which becomes united with its fellow. The ducts of the two chief 
parts unite at the median plane of the proglottis into a broad, unpaired 
yolk-duct, which passes forwards and opens into the ootyp. The separate 
follicles of the yolk-gland have a distinctly cellular wall. The yolk- 
cells are irregularly spherical or polyhedral in form. The unpaired 
ovary is derived from a paired one, has the form of a horse- shoe, with 
the concavity directed backwards, and lies in front of the shell-gland. 
The several lobules of the ovary possess walls which are formed by 
branched cells which are connected with one another by long processes 
and have the egg-cells between them, and contained, therefore, in a kind 
of follicle. The eggs have a large vesicular nucleus with nucleolus 
and chromatin framework, while their protoplasm stains intensely. 
The oviduct commences with an ampulliform enlargement ; its wall 
has a characteristic striated appearance, and consists of conical cells, 
placed on a homogeneous and pretty thick basal membrane ; their axis 
is directed somewhat obliquely to that of the oviduct. The direction of 
this axis and the structure of the protoplasm is the cause of the striated 
appearance. The vagina, the lumen of which varies in width, has con- 
nected with it a large receptaculum seminis ; beyond this the inner wall 
consists of a thick chitinous lamella, and is surrounded by a layer of 
strong circular muscles. The wall is, further on, provided with a large 
number of very fine, and probably chitinous hairs. The cuticle which 
covers the surface of the body bends round into the atrium and lines 
the inner wall of the vagina as far as the receptaculum. 
The uterus has, likewise, a distinctly cellular wall ; it extends 
forwards as far as the anterior boundary of the proglottis, where it lies 
dorsally to its axis ; as it becomes filled with ova it becomes bulged out 
laterally, and at last fills up nearly the whole of the parenchyma. The 
uterus is never branched, but only bulged out laterally. 
The testicular vesicles are from about forty to fifty in number, lie 
around the female organs, are scattered irregularly, and are most 
numerous in the most anterior and most posterior parts of the pro- 
* Zeitschr. f. Wiss. Zool., 1. (1890) pp. 555-9 (1 pi.). 
