Xll INTRODUCTION. 



Owing to fish being able to retreat into deep pools or under overhanging banks during the 

 heat of the day, or to ascend to the surface or sun themselves in the shallows when it is cool, they 

 are not so sensible to changes of climate as are mammals and birds. Advantage has been taken 

 of this, and the gold carp of China is now naturalised in most of the countries of Europe, whilst 

 the common carp, a native of the South of Europe, was first brought to England in 1514, 

 and to Denmark in 15(30 ; but Bloch observes that in his time, 1782, owing to the degeneration of 

 the species in the North, due to the coldness of the climate, several vessels were yearly dispatched 

 from Prussia to Stockholm with further supplies of Hve carp. 



Although the transport of good species of fish from England to India could hardly be expected 

 to succeed, that of the ova may more probably be attended with success. Bloch made many 

 experiments on the feasibility of fish being artificially hatched, and also as to whether it were 

 possible to cany ova. He proposed placing them in mud allowing it to dry, and thus conveying 

 it without shaking from one pond to another : his theory was based upon the supposition that as 

 fish appeared in dried-up tanks after they had become filled with rain water, the eggs must have 

 retained vitality in the mud, and that as they became moistened they vivified, and subsequently 

 hatched out. But the fish which appear as the tanks fill with water are full grown, so that 

 they must either ascend from the mud or migrate from other situations. In Europe, ova subse- 

 quent to the appearance of the eyes, can be conveyed alive, packed in bottles with wet moss, for 

 two or three days j but whether this would succeed in India has yet to be proved or disproved by 

 actual experiment.* 



The most valuable discovery as yet effected respecting the conveyance of fish ova for long 

 distances is that of James A. Youl, Esq., who successfully introduced salmon and trout into 

 Tasmania. I propose giving, from an account which he has kindly furnished to me, a short resume 

 of his most interesting experiment. 



Sie William Denison, K.C.B., then Governor of Tasmania, considering that some of the snow- 

 fed rivers of that Colony, which were almost destitute of fish, would be well adapted for their 

 residence, drew the attention of the Secretary of State for the Colonies to the subject, and he 

 deputed Me. Boccius, to make the attempt of introducing them. He tried by changing the water 

 three times daily to convey them from Europe to Tasmania, but failed. 



In the year 1854, the attention of Mr. Youl was first directed to the subject, and he came to 

 the conclusion that it was not the mature fish, but the ova or small fry alone which could be 

 successfully conveyed through the tropics, and that the aid of iced water would be indispensable. 

 Unfortunately, when commencing his first experiment, no vessel could be procured proceeding 



* How to obtain and treat fish ova, and how to hatch and rear the young, are fully detailed in Bpck- 

 lato> on "pisciculture" and several other works, so it has been deemed unnecessary to do more than introduce 

 the subject iu this place. 



