Trout Breeding. 89 



up stream and carry the fry with it, and a few sucli 

 movements will send them swirling toward the head of 

 the trough. Delicate as they are to the rough touch of a 

 feather, the swirl of water does not hurt them ; it merely 

 carries them with it and they come in contact with noth- 

 ing but water. 



A trout or salmon, newly hatched, is a beautiful thing 

 under the microscope. The circulation of blood is 

 shown more clearly than in the frog's foot, which is the 

 standard thing to use in school work ; but the frog is 

 available at all times. Under the microscope the caudal 

 heart can be seen up to the fifth day, when it is ab- 

 sorbed. The streams of blood in the sac seem to flow 

 like creeks, now dammed by a lot of corpuscles and 

 then breaking away and flowing on, while the plexus in 

 the tail shows the capillaries returning the arterial 

 blood to the veins and back to the gills for oxygenation. 



The loss in eggs is largely due to the lack of impreg- 

 nation, although some few embryos die after the eye- 

 spots show. The loss after hatching and before feed- 

 ing is largely from malformations and weaklings if 

 there has been no smothering, a thing which the expeit 

 fishculturist does not allow to happen, because his 

 trained eye detects the first sign of crowding and stops 

 it. But as all this is not written for the expert, but for 

 the beginner, all these dangers are mentioned. If the 

 beginner buys 20,000 eggs from a reliable dealer he is 

 sure that each egg has a fish in it when the lot is put up. 

 If he expects that he will hatch and rear 20,000 trout he 

 will be mistaken. Why should he expect it ? He can't 

 raise 900 chickens out of a thousand that are hatched, 

 not to mention those which died in the egg. He can't 

 average nine out of ten colts, calves or children if he is 

 doing business on a large scale, and why should he e^- 



