ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
183 
muscular apparatus is invested by large, clear epithelial cells ; in some 
examples there were seen two groups of large glands, the elements of 
which appear to be modified cells of the epithelial layer. At the distal 
extremity the epithelial cells become invaginated to form a narrow 
canaliculus, which is well ciliated in young individuals. This cavity 
swells, and so forms a kind of large space into which the constricted' 
extremity of the seminal vesicle opens. The walls of the cavity are 
glandular. There are circular but no longitudinal muscles in the 
penis ; this is a somewhat abnormal arrangement, and the author marks 
the differences by giving an account of the penial apparatus of Planaria 
subtentaculata. In Microplana some other organ is probably the copula- 
tory, and the author thinks that the function is effected by a tubercle, 
the relations of which with the muscular apparatus he was, unfortunately, 
unable to determine. The position of the ovary and the course of the 
oviduct could not be made out ; the cavity of the “ uterus ” is small, and 
is filled by a special hyaline liquid. In conclusion. Prof. Vejdovsky gives 
a review of the Dendrocoela already met with in Bohemia ; five genera 
and eleven species have been found. 
Structure of Cestoda.* — Dr. T. Pintner commences his investigation 
of the structure of the Cestoda by an examination of EcTiinohotlirium, 
which appears to be a generalized type. A detailed account is given of 
E. musteli sp. n., and shorter notices of E. typus Van Ben., E. affine 
Dies., and E. hrachysoma sp. n. 
The nervous system appears as a large ganglion placed directly 
below the rostellum, and having a central cellular mass and peripheral 
nerve-substance, which radiates out into four short frontal trunks 
superiorly, and into two large primary nerves inferiorly ; the two sets 
differ considerably from one another in their histological structure. 
The attaching lobes and the rostellum appear to be supplied by special 
nerves. The rostellum may have the form of an ellipse, the much 
longer main axis of which lies in the median plane, but in other stages 
of contraction a transverse section may be biscuit-shaped, with a similar 
orientation of the longer diameter. In the most anterior region it is 
not possible to say definitely what belongs to the rostellum and what 
does not ; but in succeeding sections the boundary is clearly marked by 
a membrane with a sharp double contour. 
This organ has several points in common with the rostellum of 
Tsenia; it is placed in the middle of the frontal surface above the 
nervous system and the cephalic loops, it is made up of several systems 
of muscles adapted to the various relations of the head and hooks, and 
is connected with an apparatus of hooks. But, while the rostellum of 
Taenia is four-rayed, that of EcMnohothrium is only two-rayed ; and the 
same is true of the hook-apparatus. At the same time, the latter must 
be regarded as completely homologous with that of Taenia, for the hooks 
have exactly the same structure, being only more delicate and having much 
less distinct root-processes ; they are arranged alternately in two layers, 
just like the rostellar hooks of Taenia, The head-stalk of EcMnohothrium 
is quite round, and slightly increases in thickness from before back- 
wards. Most externally there is a specially thick homogeneous cuticle, 
* Arbeit. Zool. Inst. Univ. Wien (Clans), viii. (1889) pp. 371-420 (3 pis.). 
