THE BERING SEA CONTROVERSY. 661 



herd. The counts of harems, and especially of cows present, are much in- 

 ferior in value. The latter counts, however, point in the same direction. 

 The harems on all the rookeries were counted in both seasons. In 1S96 

 there were 4,932; in 1897 there were 4,418, a decrease of 10.41 per cent. 

 The cows actually present on certain rookeries at the height of the season 

 were counted in both seasons. Where 10,198 were found in 1896, 7,307 

 were found in 1897, a decrease of 28.34 per cent. 



The important element in these special counts, undertaken with 

 a view to determining the relative condition of the breeding herd for 

 the two seasons, is the count of pups. All other classes of rookery- 

 population fluctuate from day to day, but the pups remain constantly 

 on shore and near to the place of birth for the first six weeks of their 

 lives, and it is merely a matter of patience and skill in counting them. 

 Such a count on any rookery is an absolute record of the number 

 of breeding females which has visited it for the season in question. 



The minimum figure of nine per cent adopted by Professor 

 Thompson is based upon a recount of a single rookery made by him- 

 self under conditions less favorable for accuracy than in the case of 

 the official counts, which give the larger figure of twelve per cent, 

 and which were made jointly by representatives of both commissions. 



8. It is not easy to apply the various counts in the form of a general 

 average to all the rookeries of the islands. We recognize that a notable 

 decrease has been suffered by the herd during the twelvemonth 1896 to 

 1897, without attempting, save by setting the above numbers on record, to 

 ascribe to the decrease more precise figures. 



This is a rather extreme statement of the uncertainty which may 

 be assumed to attach to these figures. The problem is not an easy- 

 one at best and its factors are complex. This should always be borne 

 in mind, but not to the extent of doubting the value of the figures. 

 The areas counted were large enough to be fairly typical. The counts 

 were carefully done, and are accurate enough for all practical pur- 

 poses. The probable error for the 15,000 more or less pups counted 

 would not exceed 500. But as the counting was done in exactly the 

 same manner and by the same persons for the two seasons, such errors 

 as may exist are common to both counts and the relative conditions 

 are unaltered. The figure of twelve per cent, moreover, must be 

 taken as in itself a minimum, since it is the result of a number of 

 individual counts varying in accuracy; and all in a sense underesti- 

 mates, inasmuch as more animals are always overlooked among the 

 rocks than are counted twice. 



But the exact percentage of decrease is immaterial. That it has 

 been a " notable " decrease is sufficient, and this is unquestioned. It 

 may be noted in passing that this unequivocal decrease occurs in two 

 seasons during which there was perfect enforcement of the regula- 

 tions of the Paris award. 



