ARTIFICIAL HATCHING OF SPAWN. 65 



turning round in the egg. The articulation of the 

 veins may be plainly traced. The pulsation of the 

 heart and the rapid flow of the circulation can all be 

 distinctly seen through the outer shell, forming a 

 very wonderful and most interesting spectacle. In 

 this stage, I have examined and watched the eggs for 

 hours, interested and amazed beyond measure. The 

 embryo being now alive, the eggs can be safely 

 moved ; a shock will not injure them. They require 

 little more than to be kept damp, can be packed in 

 wet moss, and sent to almost any distance with per- 

 fect safety — provided they be not placed, as some 

 that were sent to the Thames Society were, near the 

 engine-room or the funnel of a steamer, so that the 

 heat dried up the moss, and destroyed nearly all the 



eggs. 



From this time till the hatching, which takes place 

 from a fortnight to three weeks or a month subse- 

 quently, the shell of the egg gradually grows thinner 

 and thinner, and the motions and development of the 

 embryo within more rapid and constant, and more 

 clear and distinct. Some morning, when you visit 

 your trays (if the ova be on the gravel, instead of 

 under it), you observe a small reddish shining spot 

 amongst the ova, rather larger than a pellet of ova, 

 which catches the eye instantly; and on looking 



F 



