Arrnur.—On the Brown Trout introduced into Otago, 277 
extent by the temperature of the water. During the winter months the 
temperature of the water averages about 42°F.; and during the period of 
hatching it ranges from 42° to 52°. The strongest and healthiest fish 
are those which are hatched out in water at 48°. After birth the young 
trout are ready for turning out in from 30 to 50 days, but will carry best 
whenever they begin to feed, which is at an age of 25 to 28 days. 
When the young fish are about 6 weeks old and well fed, they average, 
in our ponds, 14 inches in length, and at 100 days measure 8 inches, being 
distinguished by dark bands like the fry of the salmon. In transporting 
the trout fry from the ponds to the rivers in which they are liberated, it has 
been most successfully done with fish about 1 inch to 14 inches long, the 
can of water having a sufficient quantity of watercress put into it carefully 
to prevent the consequences of shaking in transit. In this manner Mr. 
Deans has conveyed many supplies to our streams without losing a single 
trout. It has been observed with us, that in spawning, when the female has 
selected her male companion, she proceeds to a suitable gravel bed, where 
she prepares the ridd with her tail, the action of the stream assisting. She 
frequently rolls on her side and lashes the water with her tail, the ova being 
passed and impregnated from time to time, until the whole operation is 
completed. When confined they have been seen to take 8 to 10 days or 
more in spawning; but as yet I have not ascertained how long they 
naturally take in our rivers ; probably, however, not more than a week. 
Differences in External Appearance.—The differences in the external 
appearance of our trout are corroborative of all previous experience of 
these fish in home waters. Here, as there, these are due to various causes, 
such as age, sex, abundance or scarcity and also quality of food, range and 
colour of water, geological character of formation over which the river flows, 
and the season of the year. My own observations here, enable me to say 
that our trout are finest in appearances at the height of summer. By 
autumn they begin to get darker, some even I have caught were black- 
looking and lean, though all originally from the same stock. Already the 
various streams have stamped the trout with local peculiarities of some 
interest. Thus for example, in summer, trout which I have seen taken out 
of Shag River were remarkable for plumpness and good condition almost 
to deformity. They were all very bright silvery on the sides running into 
pure white on the belly, the back being grey or very light olive. Spots 
sometimes numerous and mostly of large size and black in colour, red spots 
are awanting or rare. The heads are small, even in the males, those of the 
females being beautifully shaped. The extreme fatness of form and bright 
silvery colour, I have no doubt are due to the river bottom being fine sand 
and gravel, the water clear, and the great bulk of the food being the small 
