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 leiding 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 so and 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 



