272 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



The common law enjoins on any owner of a dam which is high enough 

 to stop the passage of fish to supply a suitable fishway to carry the fish 

 over the dam. Under this law the commissioners of fisheries ordered 

 the Holyoke Company to build a fishway. The company replied that 

 it was exempt from the common-law injunction to build a fishwaj, be- 

 cause it already had paid for the fisheries destroyed above the dam, as 

 laid down in its charter. 



The court held, first, that what is not specially granted in the char- 

 ter is specially withhold; second, that the company had injured the 

 fisheries below the dam, besides destroying those above the dam $ third, 

 that it therefore was subject to the common law, and must build a fish- 

 way. 



Brookline, Mass., May, 1885. 



77.-HATt!MIIVG s \t. HON EGGS AT I?IOI\TPEI,EIER r FRANCE, ANI> 



TROUBLE WITH FUNGUS. 



By Prof. VALERY-MAYET. 



[From ;i letter to Raveret-Wattel, secretary of the Acclimation Society.] 



My salmon breeding, which began so well, has ended in complete 

 failure. I wrote you on February 14 that the eggs had arrived in good 

 condition. About the 25th hatching began, and was finished by the end 

 of the month. During the first part of March all went well, but about 

 the 10th a serious disease suddenly broke out, and nothing was able to 

 stop this epidemic, which, I believe, has for its cause an aquatic fungus 

 of the genus Saprolegnia. In short, by March 30 all were dead of this 

 disease. The white threads of the fungus must have penetrated tbe 

 gills, as I have noticed that the disease began in this region and that 

 all the dead fish had their gills thus covered. 



To what must we charge this failure ? In order to avoid the high 

 temperature of my grounds (an inclosure that had at noon between 20° 

 and 30°. C), I placed my breeding-pans in a cellar where the thermom- 

 eter ranges between 10° and 12° C. and the water never exceeded 11'° 

 C. In spite of a large opening, was that cellar too dark? This is possi 

 ble, for the fungus grows more rapidly in a rather dark place. On the 

 other hand,T could not think of putting my pans in the open air. My 

 cellar, which was light enough for a place of that nature, had a regular 

 outlet in a neighboring drain. The water has always run off in a suit- 

 able way, and I considered this sufficient. 



I must add that this was the first time that I tried hatching salmon 

 in March. Those eggs which you intrusted to me in former years, and 

 which succeeded, were hatched in December and January, during very 

 cold weather. March is a little late for a country where vegetation 

 always starts by February, and sometimes earlier. 



Montpellier, France, April 3, 1885. 



