ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
65 
much diversity of statement prevails. The epidermis is characterised 
by two sets of elements, adapted to different ends: — (a) the cuticle 
and the granular cells serving to protect the animal from the injurious 
influences of the medium ; ( b ) the club-shaped elements and free nerve- 
endings with orientating and sensory functions. Between the epidermis 
and the cutis there is a very thin basal membrane, perforated by minute 
apertures (for nerves ?) and roughened by indentations where the epi- 
dermic cells are fixed. The cutis consists of several layers of parallel 
connective tissue fibres, running chiefly in two directions. The pigment- 
layer of much branched cells lies between the cutis and the subcutaneous 
tissue. The latter consists of a loose network of connective tissue 
fibres, with fat, lymph-spaces, and nerves. The fibres pass directly into 
the connective sheaths of the deeper muscles. It stores fats and gives 
the skin a useful mobility. 
Ciliated Epithelium in Amphibian Larvae.* — Prof. 0. Mayer de- 
scribes the distribution of cilia on the surface and in the interior of 
Amphibian larvae. His results, like those of many others, show that 
ciliated cells may occur in the endoderm and ectoderm alike. As they 
occur also in different parts of the urogenital apparatus, which cannot 
be referred to either ectoderm or endoderm, it may be said that any of 
the three layers may be ciliated. 
Ostioles.f — J. J. Andeer discusses the ostioles found in the lung, 
the intestines, the synovial membranes, the peritoneum, &c., and points 
out the pathological consequences of their obstruction on the one hand 
and of their hyper-secretion on the other. 
Electric Organs.* — Hr. E. Ballowitz obtained recently two speci- 
mens of Gymnotus electricus , one specimen being in the living condition. 
He was able to make very extended observations, both on the general 
anatomy and the histology of the electric organ. 
The general structure of the organs in Gymnotus essentially resembles 
that in Torpedo and Baja. The electric tissue is formed by an extremely 
thick finely fibrous framework, which furnishes the substance of the 
papillae and villi. The whole plate is surrounded by an electrolemma 
which is especially thick on the papillae. Close beneath the electro- 
lemma there lies on the surface of the villous layer an extremely dense 
layer of delicate minute parallel rods which must number several 
millions on each plate. In contrast to Torpedo , the rods are here quite 
free from nerve- endings. 
The Gymnotus plate has three layers, an anterior papillary layer, a 
posterior villous layer, and an ill-defined middle layer between them. 
There is great variety of form and length among the villi, the longest 
being the prolungamenti spiniformi of Pacini, or the Dornpapillen of 
Du Bois-Reymond. The whole villous structure recalls that in some 
species of Baja, with this important difference that in the latter the 
nerves never extend to this surface, but keep to the smooth anterior 
surface of the plate. The nerves do not enter the substance of the villi, 
* Anat. Anzeig., xiv. (1897) pp. 69-81. 
t Comptes Rendus, cxxv. (1897) pp. 669-71. 
I Anat. Anzeig., xiii. (1897) pp. 643-8 (2 figs). Arch. Mikr. Anat., i. (1897) 
pp. 686-750 (3 pis.). 
1898 
F 
