EXPOKTATION OF IMPREGNATED OVA. 237 



the manner just now directed, may be conveyed 

 without injury very long distances — from rivers 

 in one country to rivers in another. Salmon- 

 spawn containing the vivifying germ may be taken 

 from any of the rivers of the British isles, and 

 conveyed not only to any river on the continent 

 of Europe, but to those of other divisions of the 

 globe. The time may come when it may be con- 

 veyed to Australia, Van Diemen's Land, &c., in 

 order to colonise the rivers of those countries with 

 the finest and most valuable fish indigenous to the 

 nor'ard rivers of the northern hemisphere. After 

 the ova and milt are expressed, and mixed toge- 

 ther in the sand and water of the vessel prepared 

 to receive them, nothing more is necessary to pre- 

 serve them on a voyage than a change of wa- 

 ter every twelve hours. At each conclusion of 

 that interval of time, the stale water is to be 

 poured off, and the same quantity of pure fresh 

 water substituted. 



To return to our artificial pond now ready for 

 the reception of the impregnated spawn. It 

 must be imbedded at the head of the pond — at 

 the commencement of the inclination of its bottom, 

 in a small trench about five inches in depth, formed 

 longitudinally with the current and not across it. 

 The spawn must not be laid all of a heap in the 



