TELEOSTEI 215 



going on throughout both islands, and enormous quantities of both 

 have been sent out, especially from the hatcheries of the Otago, 

 Southland, Canterbury, Westland and Wellington Societies. It is 

 impossible to estimate the numbers which have been dealt with, but 

 it is safe to affirm that the various hatcheries throughout the dominion 

 have handled over 50,000,000 young fish. This was up to the end of 

 1916 only. The Southland Society are responsible for about 8, 000,000, 

 Otago 24,000,000, Canterbury between 3 and 4,000,000, Westland 

 over 4,000,000, and Wellington nearly 7,000,000. But there are 

 altogether 28 societies in the country, and all, or nearly all, have 

 hatcheries in operation, and have been distributing trout for many 

 years past. In addition to these, several million ova have been collected 

 at the Hakataramea Hatchery for distribution, some thousands 

 going as far as the Transvaal. Between 1916 and 1921 another 

 14,000,000 ova and fry have been distributed. 



An experiment in the carriage of frozen ova was made in 1886. 

 A box of ova was placed in the freezing-chamber at the Victoria 

 Docks, London, and kept at a temperature of 18 Fahr. At the end of 

 a month it was found that, although most of the eggs had been killed, 

 a large proportion were alive apparently uninjured. To test this matter 

 further a box of ova was placed on the 'Ionic' which arrived in 

 Wellington in March, 1886. The following is Mr A. J. Rutherford's 

 report on it: 



The extremely interesting experiment of sending a box of trout ova in 

 the refrigerator is, I regret, a total failure. The sawdust round the inside 

 box was dry, and the box exceptionally well packed. Within, the moss was 

 frozen into a solid mass, the trays all being stuck together ; and on opening 

 a layer it was evident that the ova had been frozen to death. There was no 

 sign of life, and the appearance presented was like layers of light-yellow 

 transparent unfertilized ova, with one side of each egg slightly fallen in. 

 A coating of hoar-frost surrounded each egg. The animal matter was in 

 good condition, and what looked like traces of yellow dead fish could be 

 seen in many of the ova. 



I tried several experiments, such as thawing very slowly in iced water, 

 thawing in the air, i.e., but could detect no sign of vitality with a glass. 

 The ova turned opaque at once on being placed in water, but the indenta- 

 tion in the side swelled out and each egg resumed its proper shape. There 

 are about a dozen ova that have not turned opaque, and I have left them 

 in a hatching-box to see if there is any possibility of vitality. 



I think that this experiment has demonstrated plainly that the intense 

 cold evolved in the freezing chamber is fatal to life in ova, even when 

 well insulated and protected, as in the case of the box I received. 



Rate of Growth and Food Supply. When brown trout were 

 first liberated, the rate of growth was phenomenal, and this, according 

 to Mr W. Arthur, was " due entirely to new and abundant food, and it 



