On Inflammation in Fishes. 
231 
collect, from time to time, sufficient of a yellow fluid which 
presented all the microscopic characters of pus, but was 
generally mixed more or less with muscular fibre, however 
gently I pressed it along the seton track. I had made the 
wound in the largest fish too transverse, and the water 
flowed through it, so that I obtained no satisfactory results 
until I made the water so shallow that this portion of his 
back was left bare, or floated him up with corks ; I could 
then obtain some good yellow pus. 
Not only did the irritation of the setons induce the forma- 
tion of matter, but they produced a destructive ulceration 
in the smaller fish ; the substance was lost subcutaneously, 
until merely a layer of skin covered the threads, and the 
orifices of the wound grew daily wider. In the larger fish 
the tissue over the seton became of a purplish colour, and 
at the end of three weeks the latter had nearly cut its way 
out. After removing them the wounds speedily healed. 
Being now anxious to see how wounds were repaired in 
these animals, I cut a piece off the larger fish's back, taking 
care not to injure important parts, as the spine. This ap- 
peared very cruel, but so far as ordinary evidences of sensa- 
tion go, it seemed to him a matter of total indifference ; he 
would make no movement if you scratched or pressed the 
surface of the wound ; and so far from its affecting his ap- 
petite, he ate in one night twelve sticklebacks, six minnows, 
and four tadpoles, in addition to vegetables. 
For a fortnight this wound remained unaltered in appear- 
ance, except that it appeared sodden by the water ; then 
three large straight blood-vessels w^ere seen distinctly cross- 
ing it in an antero-posterior direction ; and in twenty-four 
hours they were again obscured by a thick film, which grew 
thicker and denser, and then separated, floating ofl' upon the 
water, and leaving a bright pink surface exposed ; this 
changed to a darker hue, and granulations sprang up. I 
never saw any pus on the surface even when it was kept out 
of the water, the granulations did not bleed readily, but the 
raw surface now seemed very sensitive to pain ; the unfor- 
tunate fish seemed to dread the slightest touch ; letting fall 
a drop of water over his part of the bath set him splashing 
