184 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 
These formations are to be regarded as analogous to 
certain forms of tubercle ; or, in other words, tubercle with 
its giant-cells is an inflammation-focus in which the colourless 
corpuscles heaped up at any spot (probably intracanalicular— 
Rindfleisch, Schippel), undergo a development. This, 
according to the author, is caused by imperfect nutrition of 
the cells, in so far as this is not sufficient to form new con- 
nective-tissue. According to this view, giant-cells are to be 
regarded as imperfect new cell-formations. 
The formation of intercellular substance in reticular 
tissue is paracellular, arising anew by a cutting off from the 
sides of the cells. (Dr. Stirtine, in ‘London Medical 
Record.’) 
III.—Blood.—1. Purves on the Place where the White 
Blood-Corpuscles wander out of the Vessels.—L. Purves (‘On- 
derzoekingen gedaan in het Physiol. Labor.,’ Utrecht, 1873, 
iii), to investigate the place where the white blood-corpuscles 
pass through the wall of the vessel in Cohnheim’s experiment on 
inflammation, injected a solution of silver into the vessels 
of a frog prepared after the manner of Cohnheim. The 
colourless corpuscles, without exception, wander out between 
the boundaries of the epithelioid cells. They never pass 
through the substance or through the nucleus of an epithe- 
lioid cell. According tothe author, the red-corpuscles only 
pass out by those channels which have been previously made 
for them by the colourless corpuscles. The author found no 
stomata of any kind on the epithelium of the vessels. 
(London Medical Record.) 
2. Influence of the Gaseous Contents onthe Solubility of the 
Blood-Corpuscles.—Landois (‘ Centralbatt,’ No. 27, 1874) 
says that if different portions of the same blood be treated 
with carbonic acid, oxygen, and nitrous oxide, tiie red blood 
corpuscles exhibit great varieties with regard to their solu 
bility. The corpuscles charged with carbonic acid are 
dissolved much sooner than the others. Certain reagents 
which are unable to dissolve blood charged with other gases, 
produce the “lake colour” at once in blood charged with 
carbonic acid. The reagents employed were salts of the 
bile-acids, very dilute solution of chloride of sodium, and 
serum.of dog’s blood for the blood of rabbits and guinea- 
pigs. Blood charged with nitrous oxide stands between that 
charged with carbonic acid and that charged with carbonic 
oxide. ‘The blood-corpuscles of all sorts of blood become 
round before their solution, and show exceedingly fine 
points. Perhaps the condition of the hemoglobin in the 
cells at the time may account for this. 
