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8UMMARY OF CURRENT RESEARCHES RELATING TO 
probably of an elastoid nature, staining dark with orcein, and resisting 
the action of alkalies and acids. The canaliculi do not arise secon- 
darily by absorption, but are there from the first as the bone is formed. 
Histogenesis of Cartilage in Cyclostomes.* — Prof. F. K. Studnicka 
shows that the origin of cartilage does not imply occurrence of special 
cells. In the post-embryonic life of Cyclostomes, cartilage may arise 
from (1) the dense connective-tissue of perichondrium and fascia ; 
(2) the loose connective-tissue ; (3) the so-called Schleimlcnorpel ; (4) the 
Vorknorpel (vesicular supporting tissue of Schaffer) ; (5) the axial con- 
nective-tissue of the caudal fin ; (6) highly specialised tissue, such as 
fatty tissue ; and (7) the epithelium of the notochord. 
Closing Bands in Epithelium.^ — Dr. Th. Cohn has studied the 
bands or strands (, Schlussleisten ) which close up epithelium super- 
ficially. He has found them of very wide occurrence in embryos and in 
adults, endodermic as well as ectodermic, even in epithelial-like connec- 
tive-tissue cells of the mesoderm. Their general ^occurrence, and the 
constancy of their structural character, suggest some important function, 
such as closing the intercellular spaces, but this is as yet uncertain. 
Nerve-Endings of the Sweat-Glands.:]: — Dr. P. Sfameni finds that 
the terminations of secretory nerves in connection with the sudorific 
glands lie in the membrana propria of the secretory tube, in the form of 
a network, in direct and intimate relation to the secretory epithelium. 
It is very probable that the amyeline nervous network described by 
Tomsa, Hermann, Ficatier, Coyne, and Ranvier, is formed by vasomotor 
nerve-fibres distributed on the capillaries of the glands. 
Process of Cicatrisation § —Prof. L. Ranvier has made some inter- 
esting observations on the process of healing in the cornea of the rabbit. 
Incisions made on the epithelium may be closed by direct re-union of 
the severed cells, helped by the intercellular “ cement,” but apart from 
any proliferation. The same is true of incisions in the conjunctival 
part. The cells give off prolongations which cross the gap and ana- 
stomose to form a protoplasmic cicatrix. In this case there is no cement, 
but simply a growth of the protoplasm and a fusion of its prolonga- 
tions. 
Structural Changes in Nerve-Cells.||— Prof. A. van Gehuchten finds 
that there is a dissolution of cliromatophilous elements in the protoplasm 
of a nerve-cell whenever the cell is injuriously affected either in its 
structural or functional integrity. This chromatolysis occurs within 
limits, and is not produced spasmodically ; it does not appear to be in 
any way a serious disorganisation ; it remains to be seen whether it is or 
is not compatible with normal functioning. 
Neuroglia of Brain in Fishes.T — M. — Catois finds that the support- 
ing or ependym cells, which are primitively disposed with their internal 
ends on the walls of the ventricular cavities, may in the adult migrate 
* Arch. Mikr. Anat., li. (1898) pp. 452-60. 
t Yerh. Phys. Med. Gesell. Wiirzburg, xxxi. (1897) pp. 171-200 (1 pi.). 
X Atti R. Accad. Torino, xxxiii. (1898) pp. 321-8 (1 pi.). 
§ Comptes Rendus, exxvi. (1898) pp. 308-10. 
*|| La Cellule, xiii. (1S97) pp. 315-90 (1 pi.). 
% Comptes Rendus, exxvi. (1898) pp. 433-5. 
