224 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



ductioi) of maggots we have also made use of large quantities of stale meat from 

 the markets and some barrels of fish pomace, iu addition to the articles mentioned 

 above. 



The butcher's offal comprises the livers, hearts and lights of such animals as are 

 slaughtered in Orland and Bucksport — mainly lambs and veals. These are collected 

 from the slaughter-houses twice or thrice weekly, and preserved iu refrigerators until 

 used. The quantity of such material to be had in the vicinity has been inadequate to 

 our needs and Ave have been compelled to look in other directions for food. 



The flesh of horses has been used only during the season of 1893. Old and worn- 

 out horses aud those hopelessly crippled or dying suddenly have been bought when 

 offered, and used in the same way as the butcher's offal; the parts that could be 

 chopped readily have been fed direct to the fish so far as needed, and other parts 

 have been used in the rearing of maggots. The season's experience has been so satis- 

 factory that greater use will be made of horse flesh hereafter. 



Next to the chopped meat, maggots have constituted the most important article 

 of food, aud their systematic production has received much attention. A, rough 

 wooden building has been erected for the accommodation of this branch of the work, 

 and one man is constantly employed about it during the summer and early autumn 

 months. The maggots thus far employed are exclusively flesh-eaters, mainly those of 

 two undetermined species of flies — the first and most important being a small, 

 smooth, shining green or bluish-green fly occurring at the beginning of summer and 

 remaining in somewhat diminished numbers until October, and the other a large, 

 rough, steel-blue fly that makes its appearance later and in autumn becomes the pre- 

 dominating species, having such hardiness as to continue the reproduction of its kind 

 long after the occurrence of frosts sufficiently severe to freeze the ground. 



In outline the procedure is to expose the flesh of animals in a sheltered location 

 during the day, and when well stocked with the spawn of the flies to place it in boxes 

 which are set away in the "fly house" to develop; when fully grown the maggots are 

 taken out and fed at once to the fish. The materials used for the enticing of the fiies 

 and the nourishment of the maggots have been various. Stale meat from the markets 

 has been perhaps the leading article, but we have also used such parts of the butcher's 

 oft'al and of the horse carcasses as were not well adapted to chopping; fish, fresh, 

 dried or pickled; fish pomace from herring-oil works, and any animal refuse that came 

 to hand. Fresh or slightly tainted meat has been used to greater extent than any 

 other material, and has proved itself equally good with any. Fresh fish is very 

 attractive to the flies, and when in just the proper condition may be equally good 

 with fresh meat, but some kinds of fish are too oily, for instance, alewives and her- 

 ring, and all sorts thus far tried are apt to be too watery. A very limited trial of 

 fish dried without salt or smoke indicates that it is, when free from oil, a very 

 superior article; it has, of course, to be moistened before using. Its preparation 

 presents some difficulties, but in winter it is easily effected by impaling the whole 

 fish on sticks aud hanging them up, (after the manner of alewives or herring in a 

 smokehouse) under a roof where they will be protected from rain without hindering 

 the circulation of air; in this way we have dried many flounders and other refuse 

 fish from the smelt fisheries, which are conducted with bag nets in the vicinity of 

 Bucksport. Doubtless a centrifugal drying machine might be successfully used for 



