ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 
521 
composed of “ neurosomes,” has to do with conduction, while the other, 
composed of plasmosomes, has to do with nutrition. 
Structure of Nerve-Cells.* * * § — Dr. A. Biihler gives a detailed descrip- 
tion of the minute structure of the spinal ganglion-cells in a variety of 
types. There is a granular meshwork, in the interstices of which fluid 
can circulate, an arrangement which makes it easy for food to come in 
and for waste to be got rid of. The conditions of stability in the 
framework are connected with the system of organic radii associated 
with the central corpuscles. The fibrils in the process which links one 
ganglion-cell to another are differentiations of the cell-substance serving 
as paths for the stimuli. These fibrils spread out within the cell, and 
are intimately connected, both mechanically and physiologically, with 
the cell as a whole. The basophile bodies in the cell are specific sub- 
stances connected with the nervous metabolism, perhaps in part reserve- 
material capable of reacting strongly to slight stimulus. Each element 
in the cell is under the influence of the other elements, and reacts on 
them, and the expression of their unified co-operation is nervous func- 
tion. 
Vascular Epithelium.f — Prof. F. Leydig refers to a recent research 
by Maurer in which emphasis was laid on the occurrence of capillaries 
in the buccal epithelium of Amphibians. Leydig had noticed such 
cases in his ‘ Zelle und Gewebe ’ (1885). He now calls attention to vascu- 
lar epithelium in earthworm and leech, Menopoma giganteum and Pleuro- 
delesWaltii, Ichthyophis glutinosus , &c., quoting the observations of various 
investigators on the subject. Leydig had previously pointed out the 
respiratory importance of the superficial emergence of blood-vessels. 
So-called Vascular Epithelium.f — Herr H. Joseph maintains that 
the buccal epithelium of Amphibia does not contain any blood-vessels, 
and is not vascular in Maurer’s sense. There is merely a sub-epithelial 
capillary network, the branches of which bear diverticula directed 
towards the epithelium and projecting on its base. 
Intercellular Connections in Epithelium.§ — Prof. A. Kolossow 
gives evidence in support of the thesis that the organic connection of 
cells in epithelial tissue is a constant structural characteristic, and 
suggests, though demonstration is still impossible, that the intercellular 
bridges may be important, in glandular epithelium in particular, not 
merely mechanically, but as paths for stimuli from cell to cell. 
Epidermoid Structures in Mammals. || — Prof. F. Leydig discusses 
a number of peculiar structures in the skin of .Balsena mysticetus , the 
snout of the ox, the bill of Ornithorhynchus, the snout of the mole, &c. 
He feels almost convinced that they are related to hair-structures, and 
yet they show some resemblance to the cup-organs of lower Vertebrates. 
If this last point could be demonstrated, it would, Leydig admits, point 
towards Maurer’s theory of the derivation of hairs from integumentary 
sense-organs. 
* Verh. Phys.-med. Ges. Wurzburg, xxxi. (1898) pp. 285-392 (2 pis. and 2 figs.). 
t Arch. Mikr. Anat., lii. (1898) pp. 152-5. 
X Tom. cit., pp. 167-76 (1 pi. and 1 fig.). 
§ Tom. cit., pp. 1-43 (3 pis.). || Tom. cit., pp. 156-66. 
