12 



Part III. — Seventh Annual Report 



they yielded 400 tons of bait, in 1887, 860 tons, and in 1888, 

 no less than 1033 tons, valued at £2918. This exceedingly rapid 

 increase in productiveness is apparently largely attributable to the 

 cessation of beam trawling in the estuary. 



Eeport on Bait Experiments. — Mr Fullarton also furnishes a 

 Report on the results of a series of experiments, devised by Dr T. 

 Wemyss Fulton and carried out on board the ' Garland ' in the 

 Firth of Forth, on the relative efficiency of different kinds of bait, 

 the preference by different fish for different baits, and the possi- 

 bility of discovering a cheap substitute for the forms of bait 

 commonly used. It appears that this subject has not been pre- 

 viously treated in a scientific manner, and the results are there- 

 fore of much interest. The baits used consisted of mussels, clams, 

 lug- worms, and other baits generally employed, and also earth-worms, 

 garden snails, bullock's liver, mussels preserved in boracic acid, 

 and a variety of artificial substances variously coloured, and flavoured 

 with fish extracts ; but none of these artificial baits were successful. 

 The general result of all the experiments is to show that the chief 

 best baits in the Firth of Forth stand in the following order: — lug- 

 worm, mussel, clam, horse- mussel, and limpet. Cockles and garden 

 snails were also very successful. A series of tables accompany this 

 Eeport. 



Inquiries in Connection with Inland Waters, &c. 



The Saprolegnia of Salmon Disease and Allied Forms.— The 

 pathology of salmon disease, and the many problems associated 

 with it, form one of the most important and difficult questions in 

 connection with our inland fisheries. In this preliminary Eeport 

 Dr Alexander Edington, after giving a sketch of the first appear- 

 ance and extension of salmon disease in our rivers, and a review of 

 the principal previous inquiries and investigations into the subject, 

 describes the pathological conditions of the diseased fish at different 

 stages, and the microscopical appearance of the fungus. The effects 

 of overcrowding are discussed, it being shown from an experiment 

 with a Char that the disease may occur although no overcrowding 

 exists. Dr Edington also describes his experiments in the artificial 

 cultivation of the fungus. It has been held that the disease always 

 existed in a sporadic form in all rivers, and the problem was to find 

 out the conditions under which it became epidemic. The experi- 

 ments made by the author strongly suggest that there are at least 

 two forms of Saprolegnia associated with the disease. It has also 

 been shown that the true salmon fungus can grow to a certain 

 extent in air and develop ' resting spores,' which indicates the 

 possibility of their being normally a terrestrial form. The Eeport 

 is illustrated by a plate. 



On Intercrossing in the Genus Salmo. — In'this paper a brief account 

 is given of some of the experiments which have been made by Sir 

 James Maitland, Bart., at the well known Howietoun establishment, 

 in regard to the crossing of various members of the genus Salmo. 



Besides the more important Eeports above referred to, a short 



