254 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



the abdoniiiial cavity, so far forward that they could not be forced out 

 by ordinary external pressure. The number of the eggs that we failed to 

 get from this cause rarely exceeded five hundred, and averaged not more 

 than three hundred. The rest, constituting 97 })er cent, of the whole 

 litter of eggs, came freely, with a uniform appearance of health and 

 maturity, and, in a majority of cases, not one in a hundred failed of 

 fecundation.* There were, however, during the early days of the spawn- ' 

 ing season, several females manipulated that appeared to be unripe, and 

 such, after a trial which sometimes resulted in the How of a tVw eggs 

 and sometimes not, were placed in a pen to be tried again another day. 

 In some of these cases the eggs may have been quite ripe, but volun- 

 tarily withheld by the fish ,• in the most of then), however, the evidence 

 of immaturity was conclusive. From one of these was obtained at first 

 trial three hundred eggs, of which 95 percent, were fecundated; from 

 another, one thousand eggs, and 22 per cent, fecundated. On being 

 returned to the water these unripe fish made rapid i)rogress in the 

 development of the eggs, and very soon the whole litter was ready to 

 be laid. 



It would naturally be supposed that if all the eggs of each fish attain 

 maturity nearly at the same time, the fish will, when left to follow her 

 instincts, be but a short time in depositing them ; and the phenomena 

 thus far observed seem to support that view, although from the peculiar 

 circumstances of the case they cannot be regarded as conclusive. The 

 observations on this point were not many. The salmon that came into 

 the brook, at the outlet, while waiting to be driven into the pens, found 

 themselves in water running over a gravelly bottom, had the range of a 

 portion of the brook about ten rods long, the current being moderately 

 strong, and the bottom gravelly. Here they began promptly to lay their 

 egg^, in spite of the crowded condition of the place, and when any of 

 them were left there over night, as was sometimes necessary, both the 

 condition of the females and that of the bed of the brook attested in the 

 morning their industry at egg-laying. A few full females escaped from 

 our pens and lurked in the artificial pond below, coming up in dull 

 weather, and of nights, into the running water just below the pens, and 

 laying their eggs on a fine gravelly bottom; when discovered here they 

 were promptly pursued, so that they were not long left undisturbed ; but 

 they managed to make quite large nests, and did it in a very short space 

 of time. 



The tributaries of the pond, as has been previously explained, were 

 guarded by hedges and traps, with the design of catching in the latter 

 any salmon that should attempt the ascent of the brooks. With the 

 exception of a single male caught near one of the hedges, about the 1st 

 of November, no salmon tried to ascend the brooks until after the 7th 

 of that month. On the 7th and 8th occurred a heavy fall of rain, so that 

 on the latter day the water flowed quite over the tops of the hedges, let- 



See table 9. 



