474 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
method of fixation. His results show that the connection of the neurones 
is much closer and more complicated than has been supposed. The 
whole surface of the protoplasmic part of a nerve-cell can receive stimuli 
from neurites which either form a trelliswork over the surface of the 
cell, or end on its surface in cup-shaped swellings. Both kinds of ending 
may occur on the same cell. 
Structure of Capillaries.* — Dr. Sigmund Meyer discusses the so- 
called “star-cells” (Kupffer’s cells) found in the liver. These were 
first described by von Kupffer as perivascular structures, but later he 
regarded them as the modified endothelium of the hepatic capillaries, 
specially characterised by their phagocytic importance. The author 
gives a detailed account of the researches made on the capillaries of the 
liver and of other organs, with the object of showing that the capillary 
walls display great modifications of structure in different parts of the 
body, the modifications having a special relation to the composition of 
the tissue or organ in which the capillaries occur. Observations, both 
in physiological and pathological conditions, seem to show further that 
the extent to which diapedesis, both of formed and unformed elements, 
may occur can vary rapidly, either through the direct influence of the 
surrounding fluid or through the influence of the nervous system. The 
fact of these changes may help to account for the very varying results 
obtained by different authors in regard to the capillaries of the same 
organ. 
Histology of Alimentary Canal in Dasypus villosus.j — Herr Konrad 
Koloman Helly obtained the alimentary canal of a specimen of this 
Edentate, and studied its structure in detail. The gullet is smooth- 
walled and has a thick muscular investment. The glands are very 
well developed, and are mucous glands of the usual type resembling 
those of the dog. The muscularis mucosae is remarkable, because both 
the outer longitudinal layer and the inner circular layer consist of a 
mixture of striped and unstriped fibres arranged after a fashion not yet 
described elsewhere. The histology of the other parts of the alimentary 
tract shows no special peculiarities. 
Teeth of Fossil Dipnoi.J — Prof. J. v. Rolion has investigated the 
structure of the teeth in some Upper Silurian Dipnoi, and finds that the 
dentine shows a hitherto undescribed modification. The teeth consist 
chiefly of vasodentine which resembles the corpuscles of bone very closely. 
The resemblance is such that it can only be explained on the supposition 
that odontoblasts and osteoblasts were functional at the same time, so 
that neither true dentine nor true bone was differentiated, but a skeletal 
substance without parallel among the hard tissues of Vertebrates. 
Luminous Organs, of Fishes.§ — Sigg. P. Chiarini and M. Gatti dis- 
tinguish two main kinds — electrical and glandular — and describe the 
minute structure of the latter in the present paper. The glandular 
luminous organs are found in all the Sternoptychidae and Stomiatidae 
which the investigators have examined, and in Porichthys porosissimus ; 
* Anat. Anzeig., xvi. (1899) pp. 180-92. 
t Zeitschr. f. wiss. Zool., lxvi. (1899) pp. 391-403 (1 pi.). 
X SB. Bohmiscb. Ges. Wiss., 1898, pp. 1-18 (1 pi.). 
§ Atti R. Accad. Lincei (Rend.), viii. (1899) pp. 551-6. 
