60 WORK IN THE HATCHING-HOUSE. 



the cork in the settling-tank is drawn, and the bottom of the box 

 thoroughly cleaned with a brush. 



The importance of exactly balancing the number of alevins to 

 the box, and adjusting the proportions of the hatching box to the 

 current, are apparent. There is little danger of having too many 

 alevins in a box, as the number put in is determined by the 

 number of feeding-fry that can be properly reared ; but if too few 

 alevins are placed in the box, or if they have been improperly 

 incubated and have not sufficient vitality, they will neither have 

 strength nor activity to polish the bottom ; and as with due 

 deference to the opinions of some perfect cleanliness at this stage 

 is absolutely essential to their future success in life, if they do 

 not do their own housemaids' work it must be done for them at 

 great trouble and expense. Up to this stage the 



DAILY WORK IN THE HATCHING-HOUSE 



is much the same for eggs and alevins. It is not advisable to 

 begin too early in dark mornings ; eight o'clock is quite soon 

 enough to unlock the door. The Manager should always enter the 

 house first, check the thermometers, and notice the overflows of 

 the regulating-tanks. The girls then look over the hatching-boxes, 

 pick out the opaque ova, and note the numbers on the printed 

 form, page 50. The Manager gives the head attendant a list of 

 the boxes from which all unimpregnated eggs are to be picked, for 

 sale or before laying down to hatch. If it is a bright morning he 

 sees that the swung shutters are tightly closed on the south side of 

 the house. Direct sunlight is not only injurious to the embryos, 

 but is apt to induce a cryptogamic growth on the shells of the 

 eggs. The particular fungus I have not determined, its principal 

 chai'acteristic being the length and delicacy of its filaments. 



When any eggs are near hatching, boxes which have been 

 already emptied, for sale or otherwise, are prepared ; if not, the 

 Manager is free to go to the ponds. Should the following day be 

 one on which ova are despatched, he returns in the afternoon to 

 throw the eggs on to the frame ; but on other days he merely looks 

 round in the evening to receive the schedule of the dead ova 



