On Stocking. 47 



the fact cannot be too frequently impressed that 

 first-class incubation demands such an equality 

 of temperature as can only be secured in this 

 climate by substantial masonry. 



TWO-YEAR-OLDS. 



Their Production, Appropriate Employment, 

 and Cost. 



THE PRODUCTION OF Two- YEAR- OLDS from 

 yearlings consists in the careful sizing of the 

 yearlings, and the removal of all above and below 

 a certain standard. Should this be omitted, 

 cannibalism is sure to arise, and, strange as it 

 may appear, there is more risk of cannibalism in 

 permitting a few hundreds of small yearling in 

 the two- year-old ponds than in overlooking a few 

 larger yearlings. The small trout are eaten by 

 those yearlings, who may be supposed to have a 

 larger share of original sin, and when once they 

 commence the practice they rapidly outgrow 

 their companions, and attain a sufficient size to 

 prey on the ordinary stocking of the pond. 

 These cannibals are easily known by sight; not 

 only do they appear shorter and plumper than 

 the others, but (with S. Levenensis, at least) their 

 silvery sides assume a bright golden tint. In 



