522 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Minute Structure of Glandular and Epithelial Tissue.* * * § — Herr 
K. W. Zimmermann has studied this in numerous organs. His research 
bears especially on the central corpuscles and the secretory capillaries. 
The microcentrum, although very varied in its composition, including 
one centrosome or a centrodesmosis of several, may be interpreted 
throughout, in general terms, as the motor centre, as contrasted with 
the nucleus which is the chemical centre of the cell. The microcentrum 
is a “ kinocentrum,” and the nucleus a chemocentrum. The author dis- 
tinguishes the various conditions as regards secretory capillaries ; they 
may be absent ; they may be exclusively intercellular ; or both inter- 
cellular and intracellular types may occur together. The number of 
cases in which intracellular secretory capillaries occur is much less 
than is usually asserted. 
Histogenesis of Elastic Tissue.! — M. Gardner has studied this in 
the amniotic membranes of various mammals, and has reached the 
following conclusions. (1) The elastic substance is formed entirely 
in the protoplasm of the cells, in the form of granules. (2) The elastic 
granules fuse into very delicate filaments, and this fusion may occur 
within the limits of a single cell, or in several anastomosed cells. The 
nucleus has no obvious relation either to the formation of the granules 
or to their fusion. (3) The delicate elastic filaments of adjacent cells 
fuse into a larger filament, and this is joined to two or more analogous 
filaments to form a larger fibre. (4) No active intrusion of elastic 
filaments into the extra-protoplasmic substance is observable. The 
formative cells determine the eventual reticular or fibrous structure. 
Those who do not read Russian will welcome the new journal in which 
this paper occurs ; the papers are to be published in French or German. 
Digestive Tract of Salmon.^ — Hr. G. Lovell Gulland gives an 
interesting account of the minute structure of the digestive tract of tho 
salmon, and the changes which occur in it in fresh water. The most 
striking change is of the nature of a desquamative catarrh, probably 
associated with the general state of nutrition of the fish. “ Probably 
for some time before the fish enter the river, and certainly while they 
are lying at the mouth of it, the catarrhal change begins, and begins 
clearly in the intestine and pyloric appendages ; the stomach is at that 
time unaffected. By the time the fish have reached the upper waters, 
the stomach has been attacked, and the whole digestive tract is in a state 
of catarrh. After spawning is over, the stomach is the first part to 
recover, and in the kelts it is again histologically normal, while the 
intestine and pyloric appendages probably recover when the fish have 
returned to the sea.” In no part of the alimentary canal of the many 
fish examined from fresh water, including kelts, were there any remains 
of undigested food. 
* Comparative Histology of Digestive Tract.§— Hr. Edith J. Clay- 
pole gives an interesting general account cf this, in great part based 
* Arch. Mikr. Anat., lii. (1898) pp. 552-706 (3 pis. and 14 figs.). 
f Le Physiologiste Russe, i. (1898) pp. 3-14 (2 pis.). 
X Anat. Anzeig., xiv. (1898) pp. 441-55 (12,figs.). Cf. Report of Investigation 
on the Life History of Salmon. Fishery Board for Scotland, 1898, pp. 13-22 (6 pis.). 
§ Trans. Amer. Micr. Soc., xix. (1897) pp. 83-92 (1 ph). 
