HATCHING THE EGGS. 133 



These plates represent eggs of the Coregonus fahva in differ- 

 ent stages of their growth, as seen under a powerful magnifier. 

 No. 15 represents a spoiled egg. 

 No. 20. The embryo ten days old. 



Front view of embryo eighteen days old. 

 An egg two days after impregnation. 

 Appearance of first furrow second day after impreg- 

 nation. 

 An egg showing development of furrows. 

 Mulberry form of the embryo. 

 Embryonic germ immediately after the disappearance 



of the furrows. 

 Projection of the embryo prepared with acid, 8th day. 

 Projection of embryo prepared with acid, 17th day. 

 The letters denote as follows : — 



a Shelly membrane ; b Yolk ; c Germinal vesicle ; d Yolk globules ; e Oil 

 drops ; f Albumen ; g Yolk membrane ; h Yolk vesicle ; z Head of the em- 

 bryo ; j Yolk cavity ; k Trunk of embryo ; / Tail ; in Dorsal keel ; n Dor- 

 sal furrow ; o Ocular lobes ; / Dorsal cord ; g Vertebral divisions ; r Sheath 

 of dorsal cord ; .r Cephalic bow ; t Nuchal bow ; u Trunchal bow ; v Epider- 

 moidal stratum ; x Procencephalon ; y Mesencephalon ; 2 Epencephalon. 



As too much caution cannot be observed in trout- 

 culture, I hope the reader will pardon my repeating 

 here the cautions already given : — 



To keep the covers down carefully ; 



To change the filters when dirty j 



To take out every dead ^gg once in twenty-four 

 hours ; 



To use the watering-pot freely, if sediment settles 

 on the eggs ; 



To guard everywhere against fungus. 



Transportation and Packing of the Eggs. 



Transportation of the eggs. No one need have any 

 fear about being able to transport trout eggs safely.* 



