416 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



exercised in regard to crowding them or placing one tier above another, 

 and an abundant circulation must be provided to prevent suffocation. In 

 the case in question, the eggs were two tiers deep ; the circulation about 

 the eggs of the lower tier was insufficient, and loss ensued. The mis- 

 chief, however, was almost immediately discovered, and the causes 

 removed, so that the loss did not exceed 900 eggs. 



Loss from direct rays of the sun. — The lower end of the hatching- 

 troughs extended almost to the eastern end of the tent, so that the 

 morning sun, unless the canvas covering of that end of the tent 

 was carefully kept down, shone directly into the open end of the 

 hatching-troughs. As the tent was made a thoroughfare by the In- 

 dians, and by our own household also, there was constant passing 

 through it, and the folds of the canvas were sometimes left carelessly 

 raised at night, so as to expose the eggs of the lowest compartments of 

 the troughs to the direct rays of the early morning sun. The conse- 

 quence, of course, was the loss of all the eggs so exposed. This accident 

 happened with what might have justly been called an unpardonable 

 frequency had we not all of us had our hands too full otherwise to look 

 after this source of mischief. The mortality from this cause during the 

 whole season, including both before and after we discovered the cause, 

 amounted to perhaps 30,000 eggs. 



Loss from the diffused light of the sun. — This was the main cause of 

 mortality among the eggs this season ; and it was all the more destruc- 

 tive because I was not aware before then that sunlight distributed and 

 diffused through a barrier of canvas was fatal to the life of the eggs. 

 This proved to be the fact, however. The fact was even worse than 

 this ; for the light, after passing through the canvas covering of the 

 tent, and also through the cloth covering of the troughs, destroyed the 

 eggs. This was so unexpected, and, I think, so unprecedented, that we 

 were a long time discovering the cause of the trouble. Some simple 

 experiments, however, revealed the fact that the diffused light of the 

 tent was killing the eggs. The obvious remedy, of course, was covers. 

 To provide board covers was out of the question, for it would take a 

 week, certainly, and perhaps two weeks, to get the lumber ; so I sent to 

 the nearest town for some cotton cloth, and made covers from it by 

 stretching the cloth on tight wooden frames. These were placed on the 

 troughs. The sunlight had now the tent-canvas and the cloth covers 

 to pass through, and I felt safe. But they were insufficient, and the 

 cause being of so extended a nature, and being accompanied by conse- 

 quences of a correspondingly extensive character, a great many eggs 

 were lost. Even in the few troughs to which we could afford board 

 covers, the diffused light through the cracks, reflected from the inner 

 surface of the sides of the troughs, destroyed a considerable number of 

 eggs. 



It should not be inferred from this that the total number of eggs 

 obtained in the end was reduced any by these losses. The effect of the 



