EXPERIMENTAL WORK. 265 



from the hatching-boxes. The loss with healthy fry in the 20- 

 feets, when fed by the mechanical spoons, is almost nil. After 

 August the spoons are removed, and hand-feeding substituted 

 without difficulty. The worst of the 20-feets is the small number 

 they can accommodate in whiter not more than 1200 each 

 without dwarfing the fish ; and it is advisable to thin them 

 very considerably in September. However, we find that where 

 the fry are intrinsically valuable as hybrids for experiments, or 

 foreign fish for acclimatation the 20-feets, with mechanical feed- 

 ing, give by far the best results, supplying as they do a constant 

 flow of fresh food in any desired quantity. 



The lead to the east 130-feet pond, which had been stocked in 

 October 1877 before the lead was finished, was concreted this 

 summer (1879), and the water turned in again on the 7th June. 

 A box of wood, with No. 14 perforated zinc, was supported on 

 piles in the heart-shaped well of the centre 300-feet pond, and 

 filled with earth, in which water-cress was planted. The water- 

 cress soon filled the whole well, and now forms a striking object in 

 summer, growing as it does luxuriantly out of apparently deep 

 water, no part of the box being visible. Water-cress so planted is 

 a great assistance in a fishery, as it not only improves the water 

 by removing the fishy taint, but also forms a nursery for all 

 sorts of water-snails and Entromostricce, which would otherwise be 

 unable to freely reproduce their species. This applies also to the 

 Crustacea, especially to Gammarus, of which the trout are so fond, 

 that in a plank pond above the Fishery although the stream 

 swarms with them none are ever found. 



The five rearing-boxes in the hatching-house at Howietoun 

 were fitted with deep hatching-trays ; but as the results were far 

 from encouraging, their use has been discontinued, and they fall 

 more properly to be considered under the next head. 



SEASON 1878-79. EXPERIMENTAL WORK. 



The experimental work this season was undertaken chiefly with 

 a view to economise space in hatching. Most fortunately, the 



