47U / ransactions. — Miscellaneous. 



decidedly alpine. Gneiss, slate, and volcanic rocks hem them in ; they are 

 very deep, abysmal in fact, and have very few shoals, such as exist being 

 the debris of slate or shingle. The Wakatipu and Wanaka are exclusively 

 snow-fed waters, the supply being the drainage of the nearest ranges of the 

 Southern Alps. Hayes Lake receives very little snow-water. All three 

 lakes are situated about 1,000 feet above sea-level, and bottom has been 

 found in the Wakatipu by Dr. Hector at 1,300 feet, and by Mr. Conuell in 

 the Wanaka at 600 to 1,000 feet. On the other hand, the Waihola and 

 Tuakitoto Lakes are of a totally opposite character. They occupy the middle 

 of alluvial flats nowhere 50 feet above sea-level, in fact they are affected by 

 the tides ; their bottoms are mud or silt, and they have nowhere a greater 

 depth than 12 or 15 feet of water, if so much. 



Chemical Constitution of the Water. — This is the next consideration bear- 

 ing on the well-doing and distribution of our trout. But I regret that as 

 yet it is a field for inquiry almost wholly neglected. Dr. Black, of the Otago 

 University, has very kindly analyzed several waters for me, viz., waters from 

 the Opoho Creek where our local fish-rearing ponds are placed, from the 

 Wakatipu Lake, Howell's Spring, and from the Wallacetown salmon ponds ; 

 but beyond these I do not think that the water of any of our rivers has been 

 examined, so that for the present we are tied down to the general and nega- 

 ive evidence that where the trout do well the water must be suitable in 

 chemical constituents, other things being equal. I may, however, repeat 

 here the Wakatipu analysis, which I have already given in a former paper 

 on fish culture* as it has a direct connection with facts I shall have occasion 

 to mention when I come to describe the habits of our trout. It is this : — 



Organic matter in solution. Degrees of hardness. Table salt. 



Wakatipu water, -5 grs. per gal. 3-1 Scarcely a trace. 



The absence of salt in this water is not conducive to health in trout. I 

 hope some day to be in a position to get these desiderata ; meantime the 

 only other fact of a chemical nature which suggests itself is, that our rivers 

 divide themselves into two classes — those still in their condition of native 

 purity, and those more or less polluted by the mud and silt from our gold 

 mines. 



Meteorological Conditions of our Rivers. — By this I mean such in- 

 fluences as affect our waters through their connection with rainfall and 

 snow, frost and heat, winds and atmospheric pressure. And here the 

 snoiu-fed rivers at once stand out with more or less distinctness as apart 

 from non- snow-fed rivers ; just as the muddy gold-mining waters differ 

 from the clear streams. With one exception (that of the Oreti Eiver) 

 all the snow-fed rivers of Otago, both within and beyond the limits I 



* Trans. N.Z. Institute, vol. xiv., p. 200. 



