118 



FISH Many of the fish looked, when in the water, as if covered with a halo, 



IGHTHAM. remaining at the surface nearly motionless, frequently putting their mouths out 



of the water, and turning belly uppermost immediately before death. On 



examination, the fungus was found to be most thickly matted on the shoulders 

 just behind the head, clogging up the gill openings, on the pectoral fins, and 

 tail portion of the body. Whenever ulceration had taken place, it was seen to 

 be due to the fungus, as the parts most ulcerated were those most densely 

 covered with fungus. Death was caused by suffocation in every instance. 



The last fungus epidemic which occurred at Ightham moat and ponds began 

 in the latter end of October of the present year, and continued to the middle 

 of November. About eight or ten days after it had commenced, the numbers 

 of the fish were observed to be dying, Dr. Church very kindly favoured me by 

 sending a, number of specimens that had died in the water, and also a number 

 that were affected with the fungus, but were still alive when taken from the 

 water. Dr. Church informs me that in this epidemic it was chiefly the fish in 

 the moat which were affected and died, and only a few in the lower pond were 

 observed to be affected ; none were found affected in the stews and upper pond, 

 although the stews were swarming with fish. As during the epidemic of 18/4, 

 the roach and dace suffered first and worst ; the pike, perch, and eels have not 

 been affected during this epidemic. 



The diseased fish sent to me by Dr. Church were roach, 1/ in number; 7 

 were dead when taken out of the water, and 10 were alive when taken. They 

 average 2 oz. in weight each, and were all packed in fresh grass; those taken 

 alive were put at the bottom of the box, with grass under and over them, and 

 the others at the top of the box were packed in a similar way. The fish at the 

 top of the box were overlying each other, and appeared as if they were enclosed 

 in a common envelope of fungus, and such was actually the case ; the fungus 

 having continued to grow vegetatively, had, as it were, woven the whole group 

 in a web of fungus. The new growth had a perceptible pink tint, the same as 

 I had seen upon a greyling sent to me from the river Tweed last spring, and 

 may possibly be the natural colour of the fungus when it grows in the air. I 

 confirm Dr. Church's statement that the fungus was S.ferax and identical 

 with that found tipon diseased salmon from the Tweed and Solway rivers 

 during the epidemics of 18/8 and 1879. I observed that the majority of the 

 filaments of the fungus found upon the Ightham fish were spear-shaped, very 

 few had clavate fruit heads, and I saw none with ripe zoospores, indicating that 

 the reproductive power of the fungus was feeble, and was producing only barren 

 filaments, which appears to be always the case when the epidemic has run its 

 course. 



Only four of the 10 specimens had any external blemish upon them, which 

 consisted of slight ulceration upon one pectoral fin in two, and in the caudal 

 fins of other two ; several of the rays were broken, and portions of them were 

 hanging by the filaments of the fungus. In all the specimens the fungus 

 covered the greater part of their bodies ; and the heads of several, including 

 the eyes and nostrils, were completely covered over. In none of the fish were 

 the gills affected, but five of them had the opercular opening of the gills nearly 

 closed up by the fungus. 



On opening the abdomen the viscera were seen to be white, firm in position, 

 and with a fair amount of fat upon the stomach and intestines. The roe in 

 the females was firm and clear, and though very small, it was more advanced 

 than the milt in the males. The heart, liver, and spleen were normal in size, 

 and not the least appearance of extravasation in any of the organs. On opening 

 the stomach and intestines I could not determine what the food of the fish had 

 been, as only white glairy mucus in small quantity was found in any of them. 

 The blood was perfectly normal in all, and the subcutaneous tissue was in 

 no instance discoloured, even under the thickest patches of fungus, showing 

 that up to the time the fish were captured no ulceration, or indication of any, 

 either on the head or scaled parts of the body, had taken place. The seven 

 specimens preserved and submitted to the Society will be found to be without 

 a sore or an ulcer on any part of them, which S. ferax could claim as a pre- 

 existing nidus upon which to plant itself. 



I may notice here that there seem to be two ways by which the fungus causes 

 death by suffocation. The first and quickest way is when the fungus gets 

 seated within the mouth and upon the gills at the same time, which I have 



