s Arrnur.—On Diseased Trout in Lake Wakatipu. 201 
stage or without cells, and the cells themselves were exceedingly minute, 
just visible clearly under a two-inch objective. A subsequent examination 
made since returning to town (the fungus meanwhile having been preserved 
in glycerine and boracic acid) gave similar appearances, but no Ogonium. 
It, however, revealed the fact of the spores being contained really in an 
inner sac or tube, the space between which and the outer covering of the 
main sac appeared to be full of a colourless fluid. From the appearance of 
this trout and that of others in the shoal from which it was taken, it is 
manifest that these fish are in a chronic state of disease, and that not con- 
fined to this the spawning season, for I have ascertained the presence of 
fungus at other times, as in the month of March of this year. And here it 
may be observed in passing that fungus has been found on trout at the 
Wallacetown ponds in 1876, and recently a Marlborough gentleman told 
me of his taking out of some still pools in a stream in that district 
fungussed trout years ago, while our native fish the Galawias and silver fish 
are not always free from it. At the same time the identity of the fungus 
among all those fish has not been determined. A consideration of the 
above facts naturally suggests two questions, first, what is the cause of, and 
second, what the cure for, the fungoid disease in the Wakatipu trout. 
The Cause of the Disease in the Wakatipu Trout. 
In the first place, so many difficulties surround the investigation, that 
the cause or causes of the disease cannot well be presumed to be stated 
exhaustively. At the same time, so far as our knowledge of the habits of 
trout and of the conditions necessary to their healthy life enable us to 
judge, we are warranted at least in advancing an opinion. I assume then 
that the trout in Queenstown Bay were spawned in the Town Creek, a stream 
far too small for the subsequent accommodation of the size of fish to which 
these attain. Growing too large for this stream they have naturally 
dropped down to the lake during floods, and when there have so increased 
in size in the course of a few years as to become physically incapable of 
again ascending the stream at their regular spawning season. No stream 
large enough seems to be sufficiently near, and the great depth of water 
along the shore to the west, without leading shoals, tends to confine the 
trout so to speak to one place, or at least to operate against their migration 
in that direction. In this respect the Wakatipu is totally different from the 
streams where the progenitors of our trout live in England, where the water 
does not probably have a greater average depth than four feet. With the 
true instincts of the Salmonide, however, the trout in Queenstown Bay 
linger near their parent stream, unable so to speak to convince themselves 
how it is they cannot be again admitted, and, diseased as they have become, 
presenting an appearance suggestive of the lame and sick folk of old who 
