104 THE FISHERIES OF THE UNITED STATES. 



from tbc islands in November and December. Prior to this period many of them are killed by the surf, especially 

 if the season be a stormy one, since they are not strong enough swimmers or expert enough to save themselves 

 from being dashed against the roclcs l)y tlie heavy rollers. The cows remain with their pups and suckle them, until 

 all classes have left the islands, usually by the 1st or 10th of December. It is probable that of all the seals born 

 each year an aggregate of about one half are males. The experiment was tried of examining one hundred pups, 

 taken at random from the rookeries, and in that number the sexes were about equally divided. The number of 

 bachelor seals in proportion to the cows would also seem to confirm the supijosition. 



Characteristic changes of the pelage. — Tbere is not the slightest ]>erceptible difference in appearance 

 between the seals of the two classes, either in the first or in tlie second year after thei-r birth, but as they grow older 

 they vary and diverge in the tinting of their coats, so as to be readily determined each from the other. The pups when 

 born have only short black hair, no fur. This coat is gradually replaced in their first year by a dress of fine elastic 

 fur, of a light buft" color, and of hair longer than the fur, so as to cover it completely and give that silvery-gray to 

 their sides and bellies, and that dark gray characteristic of their necks and heads. The color of their hair changes 

 in their second year to a uniform dark gray. In their fifth year the hair upon the neck and shoulders of the males 

 begins to grow coarser and longer, forming a sort of mane, which increases in length and stiffness until the animal 

 attains its full growth, during the lapse of its eighth or ninth year of life. The females are not found upon the 

 hauling-grounds with the males after they are two years old, hence it seems probable that they go from the rookery 

 in their third, and bear a pup in their fourth year. When both nm full grown the sexes differ most widely in 

 appearance; the male, weighing from four to five hundred pounds, is about three times as large as the female, lias 

 a mane, and is either black or dark brown in color. The tinting of the female is a soft, rich brown on the back and 

 sides, changing almost to orange upon the belly, and there is no mane. Tlie fur of the cows is rather thicker and 

 finer than that of the yearling seals, though the skins of young males from three to six years old are not very much 

 inferior. 



Importance of knowing the nujeber of seals. — It is of very great significance in this connection to 

 know how many seals come annually to the islands, or ratlier to understand how many may be killed for their skins 

 annually, wthout causing less to come hereafter than do at the present time. To determine how many there are 

 with accuracy is a task almost on a par with that of numbering the stars. The singular motion of the animals when 

 on shore, the great variety in size, color, and position; the extent of surftice over which they are spread, and the fact 

 that it cannot be determined exactly what proportion of them, of their several classes, are on shore, at any given 

 time; all these desiderata for comprehension make it simply impossible to get more than an approximation of their 

 numbers. They have been variously estimated at from one to fifteen millions. 



Methods of enumeration of the fur-seal. — I think the most accurate enumeration yet made is that 

 by Mr. H. W. Elliott, special agent of the Treasury Department, in 1872. This calculation is based upon the 

 hypothesis that the breeding-seals are governed in hauling by a common and invariable law of distribution, which 

 is, that the area of the rookery ground is directly proportional to the number of seals occupying it. He estimates that 

 there is one seal to every two square feet of rookery surface. Hence the problem is reduced to the simple operation 

 of obtaining half the sum of the sujierticial area of all the rookeries in square feet. He surveyed these breeding- 

 grounds of both islands in 1S7-' and IST.i, when at their greatest limit of expansion, and obtained the following 

 results: Upon St. Paul island there were G,OGO,0(IO feet of ground occupied by :h,030,000 breeding-seals and 

 their young. On St. George island he announced 32G,S40 square feet of superficial rookery area occupied by 

 163,420 breeding-seals and their young; a total for both islands of 3,193,420 breeding seals and their young. The 

 number of non-breeding seals cannot be determined in the foregoing manner, as they haul most irregularly, but 

 it seems to me probable that they are nearly as numerous as the other class is. If so, it would give not far from 

 6,000,000 as the stated number of seals of all kinds which visited the Pribylov islands during the season of 1872. 



General accuracy of these results. — It is likely that these figures are not far from the truth, but I do not 

 think it necessary myself to take into consideration the actual number of seals in order to decide the question of 

 how many can be taken each year without injury to the fishery. The law that the size of the rookeries varies 

 directly as the number of seals increases or diminishes, seems to me, after close and repeated observation, to be 

 correct. All the rookeries, whether large or small, are uniform in appearance, alike compact, without waste of 

 space, and never crowded. Such being the case, it is unimportant to know the actual number of seals upon the 

 rookeries. For any change in the number of seals, which is the point at issue, increases or decreases in size, 

 and the rookeries taken collectively, will show a corresponding increase or decrease in the number of breeding- 

 seals; consequently changes in the aggregate of pups born annually ui)on which the extent and safety of the 

 fisheries depends, can be observed accurately from year to year by following these lines of survey. 



Surveyed plats of the rookeries.— If, then, apian or map of each rookery be made every year, showing 

 accurately its size and form, when at its greatest expansion, which is between the 10th and 2.5th of July anmially, 

 a comparison of this map will give the relative number of the breeding-seals as they increase or diminish from 

 year to year. I submit with this report maps of St. Paul and St. George islands, showing the extended 

 location of breeding rookeries, and hauling-grounds upon them. These maps are from surveys made in July, 1874, 



