THE 
V 
VETERINARIAN. 
VOL. XXXIII. 
No. 386. 
FEBRUARY, 1860. 
Fourth Series. 
No. 62. 
Communications and Cases. 
AN ESSAY ON SECRETION, WITH SOME OF THE 
CIRCUMSTANCES WHICH MODIFY THAT 
PROCESS IN ANIMALS. 
By Henry Corby, M.R.C.V.S., late Demonstrator of 
Anatomy at the Royal Veterinary College. 
Head before the Members of the Veterinary Medical Association , 
during the session 1858-9, and published at the request of the 
Council. 
(i Continued from page 14.) 
Having thus sketched the structure of secreting organs 
and the composition of their secretions, we may attempt to 
give an answer to the question previously adverted to—Do 
these secretions pre-exist in the blood, or are they formed in 
the glands ? 
So far as the structure of the glands themselves is con¬ 
cerned, there seems to be no reason for denying the pos¬ 
sibility of the formation within them of new compounds not 
existent in the blood carried to those organs, the active 
agents being cells, which by their growth form the various 
secretions. We also know that in the vegetable, cells do 
effect a transformation of the materials with wdiich they are 
supplied into other compounds. But is it necessary to assert 
that they do possess this power, or can we detect the dif¬ 
ferent elements of the various secretions within the blood? 
In respect of the urinary secretion, positive evidence has 
been obtained of the existence of both urea and hippuric 
acid in healthy blood; of course only in small quantities, 
xxxiii. 9 
