How to obtain it. 225 
3rd.—Fungus attacks a fish in patches, appearing in several places 
and spreading rapidly, the colours of the fish being perceptibly less 
bright, and the general appearance leading to the conclusion that it 
may be out of health. 
There are some other typical forms of fungoid development, 
as, for instance, when it grows inside the mouth and on the gills ; 
but I will at present only deal briefly with the three cases 
mentioned above. In the first case the entire body of the fish is 
in a healthy state, therefore the fungus, which will grow on a little 
bit of semi-detached dead skin or flesh, does not extend any 
further, and finally peels off. This often happens under natural 
conditions, and without any fish-cultural intervention. 
In the second instance we have a healthy body, which from 
some cause suffers local derangement, as, for instance, from the 
effect of a bite or wound. An attack of fungus follows. 
Here the local unhealthiness of the body, accelerated possibly 
by the fungoid development, extends, it may be, rapidly, and the 
fungus extends with it. I have seen cases of this kind in which 
the fungus has gone on spreading until nearly half the body of the 
fish has been covered, the flesh on that portion appearing as a mass 
of rottenness when exposed to view. I have put the fish under 
medical treatment, and have succeeded in stopping the progress of 
the fungus, and even in driving it back a little, but such a fish is 
usually too far gone, and dies under the treatment. The effect, 
however, is often to cause a cracking or breaking of the skin, and 
a partial separation of the diseased portion of the flesh. The 
process of sloughing in reality begins, but the mischief having 
gone too far the fish has not power left to throw off the diseased 
portion, but simply makes an attempt to do soand dies. In cases 
of a milder form which I have treated the sloughing process has 
been successfully completed, and the whole patch of disease, both 
fungus and skin, has peeled off, the wound has been carefully 
treated with carbolic acid, and the fish has recovered. 
In the third case we have an unhealthy fish which is attacked, 
and, as the whole body is practically in a fairly good condition for 
the fungus, we find it growing in several places simultaneously. 
It sometimes takes but little to place a fish under such conditions. 
Wild fish, caught and placed in a small tank, for instance, and 
Q 
