SCIENTIFIC SUMMARY. 
101 
enlarged in tlie region of the disc. (4) In recent cases the disc looks red or 
roseate. (5) The obscuration of the retina ceases, hut the arteries and veins 
become smaller and the contours of the disc lose their regularity, and are 
fringed by streaks of pigment. — Vide Ophthalmic Review, October. 
Development of Epithelial Cancer in Internal Organs . — Dr. Otto Weber 
finds from researches made in the liver and lungs, that secondary cancroid 
deposit exists in internal organs much more frequently than is believed. The 
epitheliomata in internal organs, he says, are developed at the expense of the 
nuclei of the interstitial connective tissue, and not of the proper epithelial 
cells of the organs. He gives several instances of the co-existence of epi- 
thelial cancer and tubercle in the same organ. 
Structure of the Kidney . — M. Chrzonszcewsky combats Henle’s ideas on 
the structure of the kidney. He injects carminate of ammonia into the 
jugular vein of a rabbit ; the carmine passes into the vessels and thence into 
the uriniferous tubes and the urine. To colour the vessels alone he ties the 
renal veins immediately after injecting the jugular, then the artery; to 
colour the uriniferous tubes only, he ties the ureter, and injects through the 
renal artery a saline solution, which removes all the colouring matter depo- 
sited in the vessels of the kidney. The principal results at which he has 
arrived are the following : — The uriniferous tubes end in three ways — in 
anastomoses, in culs-de-sac, and in the Malpighian corpuscles. The anasto- 
moses, which are very numerous in man, in the calf, and in the pig, are 
met with chiefly in the cortical substance. The termination in cul-de-sac 
is very rare, but there is no doubt of its existence. The Malpighian cor- 
puscles (or rather capsules) are continuous with the tortuous tubes alone, 
and each with only one. The Malpighian capsule is lined with pavement- 
epithelium ; the internal surface of the glomerulus of vessels is also covered 
with epithelium, but of larger cubic cells, more resembling the tortuous 
tubes. The Malpighian capsules communicate with the flexuous tubes, and 
through them with the straight tubes ; and all may be injected through 
the ureter. In the looped canals described by Henle two kinds are to be 
distinguished : 1. Some described already by Perrein, found in the peri- 
pheral portion of the medullary substance, are merely loops of flexuous 
tubes burying themselves in this substance ; 2. Others, reaching the sum- 
mits of the pyramids, are merely vessels. 
Production of Anencephalic Monsters. — M. Dareste, well known for his 
researches in teratology, has published a very able paper on the cause of 
these monsters. It appears that two theories have hitherto been framed to 
account for these phenomena, and it seems that though those two hypotheses 
apparently contradict each other, M. Dareste’s discovery has harmonised 
their more important points of difference. It was thought by Haller and 
Morgagni that the cause lay in the existence of a dropsy of the spinal cord, 
which tended to destroy the nervous substance. Geoffrey St. Hilaire, on the 
other hand, looked upon the cause as an arrest of development. Both hypo- 
theses are in some measure correct, according to the results of M. Dareste’s 
enquiries ; but Haller and Morgagni erred when they said that the effusion 
destroys the nervous substance. In point of fact, M. Dareste has discovered 
that the effusion appears before the nervous substance, and thus hinders its 
development. But this distinguished physiologist has gone a step further 
