238 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



desirable to test the efi'ect of confinement in a pond of this character. 

 It is a [)iece of water abont sixty acres in area ; is very deeply colored 

 by the exudations of extensive meadows that drain into it, and its bot- 

 tom, except a narrow belt along part of the shores, is composed of soft, 

 peaty mud. The brook by which it discharges into the Penobscot is 

 of saflicienl volume to drive a grist-mill during the greater part of the 

 year. Three of these fish were found in this brook at the breeding sea- 

 son, and, as several nests were seen, it was supposed that others had 

 descended from the pond unobserved. But a single one was caught. 

 This one was a male, in excellent condition, and in color much richer 

 than any caught elsewhere. Thus the various mishaps of the season 

 left us for a breeding stock only the eighteen fish in the pound at Craig's 

 Pond Brook. 



As the breeding season approached, ijreparations for the development 

 of the eggs were made by fitting up a room in the basement of an old 

 mill at the mouth of Craig's Pond Brook. Water taken from the open 

 brook, which, though of small volume, is impetuous in character, dashing 

 down over a ledgy bed, was led through several wooden troughs, each 

 18 feet long, 15 inches wide, and 8 inches deep. Grilles, made by setting 

 narrow strips of window-glass on edge in wooden frames, were placed 

 in these troughs, about an inch from the bottom. The eggs, when de- 

 posited on the grilles, arranged themselves in rows across the trough, 

 each row lying on the edge of a glass rod, and between two other rods. 

 The space underneath the grilles allowed the constant jyassage of a cur- 

 rent of water, preventing stagnation, and a like current passed over the 

 grilles. No attempt was made to filter the water, it being already un- 

 commonly clean for brook water. 



On the 2d of jSTovember the breeding fish were for the first time 

 seined out from the pound and examined. There was no indication that 

 any of them had begun to spawn, although if kept there many days 

 longer it is not unlikely that they would have deposited a part of their 

 eggs on* the clciai, saiidy bottom. All of the males were found rij)e ; 

 several of the females partially so, an<l 12,500 eggs were taken and 

 fecundated. The fish were all returned to the pound to be seined out 

 again another day. The work was continued daily until Noveuiber 10, 

 when all the ripe fish on hand had been deprived of their eggs, with a 

 single exception. From one of the females we failed to obtain any 

 eggs, and at last cam<' to the conclusion that she was quite barren. 

 She was, however, kept in the brook, and occasionally examined, until 

 December 12, when she gave a few eggs that were apparently good, 

 but could not be tested for want of milt. Dissection then showed that 

 her ovaries contained a small number, probably a thousand, eggs, of 

 nearly or quite full size and healthy appearance, and a much larger 

 number that were not half grown. With this exception all the females 

 yielded full litters of eggs, that came with ordinary ease, and were, as 

 the result of incubation showed, in a state of complete development 



