46 FISH AND GAME. 



them. The superintendents at the different stations, whenever 

 the work at hand will permit, are always willing to show vis- 

 itors around and give them all needed information. 



Fish Diseases. Numerous cases of fish diseases have been 

 brought to our attention during the past three years, and 

 efforts have been made to determine their cause and to in- 

 stitute methods of prevention. Fish are subject to a number 

 of parasitic diseases, especially at the hatcheries, where they 

 are kept in closer confinement than in the natural state, 

 necessitating constant supervision. 



Fish Propagation. 



Distribution. A number of our native fish are not being 

 propagated, but there are additional possibilities in the trans- 

 planting of valuable fish from waters where a species exists in 

 quantities too great to permit proper development, as, white 

 perch, horned pout, etc., and also in the introduction of species 

 like the pike perch and black bass from other States into 

 Massachusetts waters. Experiments should be made along these 

 lines to see if many other valuable species are not capable of 

 being reared in Massachusetts waters as successfully as our 

 native fish. 



The relative advantage of planting fry or fingerlings in our 

 inland waters is a question upon which eminent fish culturists 

 have radically disagreed, and forcible arguments have been pre- 

 sented by the advocates of both systems. Certain species, for 

 example, pike perch, owing to their cannibalistic tendencies, can 

 only be planted in the fry stage, while others, particularly the 

 trout and salmon, can readily be reared to fingerlings. Your 

 commissioners have found that from a practical standpoint both 

 systems should be followed, as under the present circumstances 

 it is most conducive to success to plant both fry and fingerlings. 

 The fingerling method undoubtedly is more successful and cer- 

 tain, especially as applied to larger streams, but in addition 

 fry should be used for smaller brooks and headwaters. At the 

 present time our hatcheries are producing their full capacity of 

 fingerlings, but a greater number of eggs can be hatched to the 

 size of fry than can be raised to the fingerling size. Therefore 



