13 



Week ending — 



Average Tem- 

 perature of Water 

 (Degrees F.). 



Marcli 6, 

 March 13, 

 March 20, 

 March 27, 

 April 3, 

 April 10, 

 April 17, 

 April 24, 

 May 1, 

 May 8, 

 May 15, 

 May 22, 

 May 29, 

 June 6, 

 June 13, 

 June 20, 

 June 27, 

 July 3, 

 July 10, 

 July 17, 

 July 24, 

 July 31, 



36.8 

 38.0 

 43.0 

 49.5 

 49.6 

 46.9 

 48.0 

 60.1 

 61.6 

 62.3 

 55.8 

 67.3 

 66.1 

 62.5 

 61.6 

 61.3 

 64.4 

 67.2 

 67.4 

 67.6 



Development. — When the eggs are deposited on the natural 

 beds they are at once covered with milt, which the male scatters 

 by thrashing his tail. The eggs then adhere to the suitable 

 objects on the bottom in such a way that it is impossible to 

 gather any appreciable quantity for hatching purposes. On 

 "stripping" the fish for artificial fertilization the eggs adhere 

 to each other and form masses until "hardened" by frequent 

 washings. 



The period of time which it takes artificially fertilized eggs 

 to hatch at 72° F. ranges from forty-eight to ninety-six hours. 

 The first lot of 8 ounces was placed at the Sandwich Hatchery 

 June 25, 1919, and in forty-eight hours one-half had hatched, 

 80 per cent of the eggs proving fertile. In the surface water 

 were thousands of tiny alewives with food sacs, nearly trans- 



