ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
463 
The nervous system consists of a pair of strongly developed longi- 
tudinal cords, which extend on either side of the body from one end to 
the other. They give off branches onf either side. No nerve-cells can 
with certainty be detected. The excretory organs consist of a network 
of tubes, the larger of which contain cilia. Each vessel is lined by a 
clearly outlined membrane-like layer which, in appearance, more 
resembles a fine cuticular structure than anything else. From one side 
a tuft of cilia projects into the lumen. In longitudinal section these 
cilia are seen to form a continuous line along one side of the vessels, and 
are apparently connected at their bases with cells, the nuclei of which 
can be detected. There are no structures to be found resembling the 
“ flame-cells ” of other Cestodes or of Trematodes, and another point of 
distinction is to be found in the position of the vessels which are for the 
most part placed in, and not superficial to the central core of connective 
tissue. After long search the author found, what Wagener failed to 
see, the external openings of the excretory system ; they are on the 
ventral surface, one on either side of the body, and slightly in front of 
the external opening of the uterus. It is possible that there is more 
than a single pair of orifices. 
Amphiptyches is hermaphrodite, and only one set of organs is present. 
It is doubtful whether it is self-fertilizing, as with the single exception 
of Caryophyllseus, it alone among Cestodes possesses a definite recep- 
taculum seminis, a structure characteristic of not-self-fertilizing 
hermaphrodite animals. Wagener regarded this receptaculum as the 
testis. The real testes are a series of somewhat globular saclike 
structures which are scattered about irregularly in the posterior part of 
the body. Fine ducts, very difficult to distinguish, and probably only 
fully developed when the spermatozoa are actually in the act of transit 
to the exterior, pass from the testes into a common duct on each side, 
which again opens into a coiled tubular organ ; this last is to be 
regarded as a vesicula seminalis. The tube into which it opens is 
probably eversible. 
The coiled tubular uterus is the most prominent structure in the 
body. The ovary consists of a series of somewhat small grapelike 
ovaries, whence ducts pass into a central somewhat saccular organ 
filled with ova, which appears to hold the same relationship to the ovaries 
as the vesicula seminalis does to the testes. Each little ovary, when 
the ova are not fully formed, has the structure of a multinuclear mass of 
protoplasm which only subsequently becomes divided into a number of 
distinct cells. The yolk-glands consist of innumerable dark brown 
small spherical masses ; they are distributed plentifully along the sides 
of the body. There do not appear to be any definite shell-glands. 
Larvae of Bothriocephalus in the Salmon.* — Dr. F. Zschokke de- 
scribes five larval forms of Bothriocephalus sp. from the salmon of the 
Rhine. These seemed referable to several different species, but not in 
any case to B. latus. Two infection experiments with two different 
larval forms yielded no result. The larvae are by no means frequent in 
Rhine salmon, for only three fishes out of ninety-three examined con- 
Centralbl. f. Bakteriol. u. Parasitenk., vii. (1890) pp. 393-6, 435-9 (5 figs.). 
