BULLETIN OF THE UNITED STATES FISH COMMISSION. 59 



not fed, and it is scarcely probable that the excrement of geese, which 

 during summer wander about the banks and swim on the pond, and 

 consequentlj" feed altogether on grass, furnishes any food for the fish. 

 Some water also flows into the pond above ground; along the edges 

 grow Glyceria fluitans and J uncus, and Confervce rest upon the water. 

 Fishing in this pond is carried on by means of bow-nets, a seine, and 

 spears. Large pike and perch do their share to i)revent the over- 

 crowding of the pond. This jjond furnishes another proof that every 

 exhausted peat-bog may be used as a fish-pond, if it contains water. 

 Such bogs, however, must admit of fishing ; no edges of peat should 

 therefore be left, and the refuse should not be thrown into the 

 pond, but carried away and used as manure. Such ponds, which have 

 formerly been j)eat-bogs, are found in many places, and are absolutely 

 useless as long as not stocked with fish. Every farm might have fish- 

 ponds, if people would take more interest in this matter, and would 

 display more energy in transforming these exhausted peat-bogs, over- 

 grown with poisonous weeds and full of parasites, into fish-ponds, 

 yielding a revenue. 



CASTRATING FISH.* 



By HERR WEDDIOE. 



[From "Deutsche Fischerei-Zeitung," volume iv, No. 1, Stettin, January 4, 1881.] 



The writer of these lines has years ago spoken to fishermen and 

 advised them to make experiments regarding the possibility and jirob- 

 able success of the castrating of fish by removing the roe or the milt. 

 This matter has also been spoken of in the "Deutsche Fischerei-Zei- 

 tung," p. 483, but, as far as known to tbe writer, no such experiments 

 have been made. It is probably not very diflicult to remove the roe or 

 milt from live fish, but of course it will be necessary to exercise great 

 caution in doing it. The belly would have to be ripped open with a 

 very sharp knife, the roe or milt would have to be loosened verj' care- 

 fully without injuring any other organs, and the cut would finally have 

 to be sewed ui) with the greatest care. It is probable that the wound of 

 a fish treated in this manner will heal very soon. The nutricious mat- 

 ter which would otherwise have served for forming roe or milt will cer- 

 tainly cause a more rapid increase of flesh and fat, and therefore an 

 equally rapid increase in the weight of the fish. For such experiments 

 young, but full-grown, fish should be selected (jjerhai^s two or three year 

 old trout) whose generative matter has not yet been fully developed 

 (the time for trout would therefore be April and May). i!s"one should 

 engage in such experiments but those who possess the necessary leisure 

 and knowledge. If such experiments should prove successful, the cas- 

 trating of a large number of fish will possibly prove an advantage to 



* ^^ Kastrirung von FiscJien." — Translated by Herman Jacobson. 



