46 



Ice was then freely placed in the transverse open trough at the upper end of 

 the gravt'l beds and the temperature thus reduced to 44 ° . About four o'clock 

 on Thursday the 21st April the first box of ova was opened, and, to the dismay 

 of Mr. Kamsbottom, a very large proportion of the eggs were dead ; but in the 

 second and third boxes affairs looked more hopeful, and by the time a dozen 

 were unpacked, it was manifest a large jjroportion would be saved. In unpack- 

 ing, as soon as the lid of each box was unscrewed, the top layer of moss was 

 quickly removed and the lower layer of moss with the ova was then lifted 

 out, and at once turned upside down on to the cool water running over the 

 gravel beds. By this means the ova soon separateil from the moss and dis- 

 tributed themselves amongst the gravel, after which the moss was carefully 

 removed bit by bit. Mr. Eamsbottom aud myself continued unpackmg by 

 candle-light through a great portion of Thursday night and renewed the work 

 at dajdight on Friday morning. By Friday night the last of the boxes were 

 finished and Mr. Ramsbottom calculated that about 35,000 living and healthy 

 ova were safely deposited. Of these only about 150 were trout ova, which wore 

 placed in a separate gravel bed constructed on purpose and enclosed at each 

 end by perforated zinc. 



The ova placed in the small boxes were obtained and packed by various 

 persons in different parts of Great Britain ; and it is a highly gratifying fact 

 that the boxes packed by Mr. William Kamsbottom himself contained a far 

 higher percentage of living ova than any of the others, thus proving that 

 he had profitted greatly by the experience gained in the experiment tried in 

 London. 



The percentage of living ova varied greatly in the different boxes ; but the 

 largest number were invariably found in the boxes in which the ova were 

 more thinly scattered amongst the moss and were subjected to only just 

 enough pressure to keep them steady. 



During the unpacking on Thursday night several living ova were unavoidably 

 picked out and left in the heaps of damp moss besides the gravel beds through 

 the night. On searching the heaps of moss on Friday morning I recovered 

 several ova from amongst the moss, and one or two from the stones underneath, 

 and transferred them safely to the water. 



Bedded in the moss of one of the boxes I found an English wasp which 

 evinced slight signs of animation. On placing the insect in the sun for a 

 few minutes it became quite lively and walked quickly away. It is true that 

 wasps are scarcely desirable subjects for acclimatisation, but svirely this cir- 

 cumstance ought to teach us a \isef ul practical lesson as to introducing valuable 

 insects or other low organisms especially in their embryonic stages. 



A few of the boxes of ova had been placed in the vaults of the Wenham-lake 

 Ice Company for six weeks before the "Norfolk" sailed; and in these boxes, 

 though a larger percentage of the ova were dead, the eyes of the fi.sh were 

 distinctly visible in those which were living — the development of the embryo 

 having reached a higher stage. The ova from one of the boxes were placed in 

 an ingenious apparatus prepared by Dr. Officer close to the ponds. This ap- 

 paratus consisted of two tubs of gravel upon which the ova were placed, 

 the whole being so arranged that a small stream of iced water flowed from a 

 cask through each tub. 



Before the whole of the ice was used up the temperature of the water in 

 the River Plenty fell to 42 ° and has averaged about 47 ° since. The only 

 object in cooling the water with ice at first was to prevent the transition of 

 temperature being too sudden. It speaks volumes for the arrangements here 

 that the percentage of living ova now in oui* breeding ponds is larger than was 

 obtained at the same stage in the experiment in London although they had not 

 in that instance undergone a sea voyage. For several days after the deposi- 

 tion of the ova Mr. Ramsbottom was busily engaged in removing all dead 

 ova and pieces of moss, charcoal, &c., from the gravel beds. For several days 

 afterwards the average death rate was a mere fraction. During the last few 

 days the rate has slightly increased, which was to be expected as the mortality 

 is always greater when the ova are on the point of hatching. 



The development of the bulk of the ova has been visibly progressing up 

 to the present time and on the 4th instant Mr. Ramsbottom had the high 

 gratification of seeing the first trout burst its egg in Tasmanian water, and, 

 on the following day, the first salmon. 



tip to the present time about 7 salmon and 23 trout have been seen free of 

 the egg, but it is impossible to give any estimate of the number now hatched, 

 as the instinct of the little creatures warns them to wriggle away out of sight 

 under the gravel, and thus many escape detection for the first few weeks 

 of their existence. 



