On S toe kino-. 35 



Ventilation is provided by little cylinders of perforated zinc 

 soldered round an aperture in the lid and guarded by its 

 handle. This in practice has been found sufficient. 



' Carboys are used by some pisciculturists, and, when well 

 filled with water, there is no jar ; they keep a very equitable 

 temperature, the thick glass being a bad conductor, besides 

 which they are generally packed in a basket. The only 

 objection I have to them is their weight, and the space they 

 occupy in proportion to the number conveyed. Fry appear to 

 travel by sea fairly well in carboys ; while, in conical 

 travelling tanks, they appear to suffer from the motion of the 

 steamer. During the Edinburgh Exhibition of 1881, some 

 thousand fry of Coregoni arrived in good condition from 

 Russia. They were carried in a modified form of carboy 

 packed in a square box lined with felt, air being admitted by 

 a tube passing through a cork. 



' Conical tanks have one advantage in warm weather ; if a 

 jacket of coarse sacking be laced tightly over the tank, and 

 the lid arranged so as to admit sufficient water to escape to 

 keep it damp, the evaporation will cool the tank so that the 

 temperature seldom rises above 45. The best temperature 

 for travelling fry is, I think, above 40, and certainly below 

 50. I do not think it ever advisable to reduce the tempera- 

 ture of the water in the travelling tank below that at which 

 the fry are being reared, which is usually below 50.' 



FRY : ITS APPROPRIATE USES. The cases in 

 which fry are preferred to Ova sown in redds are 

 few ; but in the case of district Boards where the 

 heavy cost of yearling ponds makes it impossible as 

 yet to rear the fry, the best course is to make redds 

 in the upper and less accessible waters for one half 

 the eggs incubated, and to feed the remaining 

 half as fry until the beginning of the fourth 



