We have already noted that in that portion of the period, 1871 to 1889, which falls prior to 1884, thirteen years in all, no difficulty was experienced in securing the full quota, and it may be added that this was completed not later than July 20th. A retardation of the date at which the quota can be filled is a direct indication of the degree of exhaustion of the hauling grounds. In marked contrast with these earlier years stand the conditions of 1896 and 1897, when greatly reduced quotas only were obtained, notwithstanding the unusual prolongation of the driving period. The statement here made that the difference between the quotas of 1896 and 1897 is not an actual measure of decline in the breeding herd requires explanation. The quota of any year is dependent upon the birth rate of three years previous, killable seals being males of approximately three years of age. The difference noted, therefore, while not indicative of the actual decrease for the seasons 1896 and 1897, is a direct measure of such decrease for the seasons of 1893 and 1894, when the seals in question were born. That the rate of decline as thus shown was greater in 1893-'94 than in 1896-'97 is explained by the fact that, whereas only 30,000 seals were taken at sea in 1893, 60,000 were taken in 1894; while in 1896 43,000 were taken as against only 25,000 in 1897. In other words, the pelagic catch of 1894 exceeded that of 1893 by one hundred per cent, while that of 1897 fell seventy-two per cent below that of 1896. It is not, therefore, strange that the quota of 1897 should show a reduction of thirty per cent as against one of twelve per cent in the breeding herd for the same year. 3. From these data it is plain that the former yield of the hauling grounds of the Pribilof Islands was from three to five times as great as in the years 1896 and 1897, and the same diminution to one third or one fifth of the former product may be assumed when we include also the results of the hunting at sea. This proposition needs little comment. It is a simple deduction from the conditions of the preceding paragraph. The minimum estimate of former conditions is the lowest possible figure that could be in any way defended. The larger figure is apparently more nearly correct. The quota of 1898, of which we now have the record also, was about 18,000. It is not so stated in this paragraph, but the inference is inevitable that what is thus given as the decline of the "yield of the hauling grounds" is equally the decline of the breeding herd. A breeding herd which yielded without difficulty annually 100,000 killable animals (superfluous males of three years of age) must be reduced to something like one fifth its former size when it is able only with extreme difficulty to yield a quota of 20,000 such animals.