Trout Breeding. 85 



embryo fish lie quietly on these frames because there is 

 but little light, a thing they avoid, but if the "rabbet" 

 for the wire-cloth is deeper than one-sixteenth of an 

 inch, letting the wire in deeper, there will always be 

 some fry on top of the frame below to bother by escap- 

 ing when cleaning. A trough full of these trays does 

 not show up much "business" to a visitor, but it is of 

 use when the hatchery is crowded. 



Unimpregnated Eggs never change from the time 

 they are taken until they turn white, which they may 

 do at any time, often not until hatching begins. ¥/ith a 

 microscope I can see the change in' a trout egg at three 

 days old and with the eye at ten to twenty days, accord- 



Smaller Tools of the Craft. 



ing to temperature. At first all the eggs have a ring at 

 the top ; no matter if it is rolled over the ring will come 

 up. The first sign of impregnation under the micro- 

 scope is a division of the yolk into halves and then 

 quarters; then comes the "mulberry mass," and after- 

 ward the line of the backbone and the eyes. But the 

 Qgg with no fish in it, if it has not turned white, holds 



