Gently ueging Natceb. 





391 



Stkipping a Tkout. 



the abdomen being in this case also inserted in the water. 

 After stirring the contents of the bucket with the hand, the 

 water should be poured off and fresh supplied several times 

 in succession, until no trace of the milt can be seen, always 

 taking care to keep the ova submerged. The spawn may 

 then be moved to the hatching-ground or boxes ; for the arti- 

 ficial spawning-bed may be made in a ditch, dug for the pur- 

 pose, and paved, and supplied through pipes with water, as 

 well as in boxes ; but experiments have given the preference 

 to boxes, as susceptible of forming thereby a stream more 

 equal in flood, volume, and temperature. In the removal of 

 . the ova for a short distance, it is unimportant in what man- 

 ner they are conveyed, so long as they are not much shaken. 

 In transporting ova a great distance, it should be done in 

 the winter or spring, placed in tanks lined with sponge and 

 swamp-moss, with an aerating pump placed in it for frequent- 

 ly moving the water, changing it, and exposing it to the air. 

 Fecundated ova have been packed in moss by Setli Green and 

 sent by mail a thousand miles, and then hatched with very 

 small loss. ' 



