THE FORMATION OF PUS. 
811 
are beyond control; the real object, therefore, of the vete- 
rinary surgeon should be to prevent their occurrence. This 
can only be done by one who pays frequent visits to the farm, 
gives close attention to all the details of management, and 
has an intimate acquaintance with the system of farming 
which is adopted. Knowledge of this kind will be of the 
utmost value to the veterinarian who is called in to suggest 
preventive measures, and it can only be acquired through 
the medium of close observation, which is only possible 
under the contract system. We do not mean to assert that 
at present veterinary surgeons would not be permitted to 
observe and analyse as much as they please ; but we do 
mean to suggest, what is perfectly evident, that they would 
not be paid for the time thus expended, and we do not 
expect that veterinary surgeons, any more than members of 
other professions, will devote themselves to investigations 
which, however important, are not of a kind to supply the 
means whereby they live. 
The care of the live stock of the country, we have often 
contended, should be in the hands of qualified men, and we 
should expect that the general acceptance of the system 
suggested in Mr. Neville-Grenville’s letter would effect this 
very desirable object, but in saying thus much we hardly 
indulge the hope that the present generation will see the 
system in effective operation. 
Extracts from British and Foreign Journals. 
THE FORMATION OE PUS. 
Pus was formerly considered as an altered liquor san- 
guinis, in which the fibrin has assumed a molecular and 
corpuscular form. The corpuscles were looked upon as 
having much resemblance in size and general appearance 
to the white corpuscles of the blood, though the circum- 
stances which determine the change of fibrine into corpuscles 
of pus were not established. It has more recently been sup- 
posed that the pus-globules were the result of the prolifera- 
tion of the corpuscles of the connective tissue. But Cohnheim, 
in 1867, maintained, after experiments, that pus-globules are 
simply leucocytes, or white corpuscles of the blood, which 
