Weights of yearly growths In carps 76 



Weir baskets , 87, 192 



Wheat bran 133, 134, 138 



Wheel animalcules (Rotiferae) 11, 32, 35 



Wheel tractor 159« 



Whirling disease 63, 95, 99, 102, 122, 12A, 135, 206, 206» 



White-fish (marane) eggs, development time of , 115, 116 



Whitefish meal 139, UO 



White-fishes (Coregonus), nutrition of 14 



Wielenbach fertilizer investigations , 167 



Wild ducks 93 



Winter fallomiess 158 



Winter ponds (hibernation ponds) 182«, 182 



Winter sleep (hibernation) A, 181, 197, 203 



Wollhand-crab groats 1/J 



Tforking costs 189 



Worm, band (Schistocephalus) 209 



Worm cateract of the eye 189, 208 



Worm-parasitic diseases 207 



Worms 31, 3A, 35 



Worms, bristle 13, 31, 3^, 35 



Wonus, mud-tube (Tubifex, Limnodrilus) 31, 35 



Xanthorism 91 



Yearly grovf ths in carps , weights of 76 



least 138, UO 



Yeast, dry 138 



Yellow edge ( Dytis cus ) 3A 



Yield and age of ponds 31, -158, 159 



Yield classes 127, U5 



Yield, gross 189 



Yield, gross natural 126 



Yield (natural) of German pond industries 126, 127 



Yield, net 189 



Yield per hectare and fish stock density 129 



Yield per hectare and maintenance requirement 129 



Yield, see also hectare yield, increase, total increase, natural increase, 

 natural yield, natural gross yield, 



Ziemsen weed-saw 156 



Zinc 110, 126, 18^1 



Zinc sheet, perforated 68'» 



Zinc sheet, source of supply for 68 



Zooplankton (animal plankton) 34, 35) 36, 37 



Zuger glass brooder 113-)*- 



Zuger glass breeders, source of supply for 112 



260 



