ALASKA INDUSTRIES. 79 



The discovery, at the close of the season of 1872, of this law of dis- 

 tribution gave me at once the clue I was searching for in order to 

 take steps by which I could arrive at a sound conclusion as to the 

 entire nvimber of seals herding on the island. 



I noticed, and time has confirmed my observation, that the period 

 for taking these boundaries of the rookeries, so as to show this exact 

 margin of expansion at the week of its greatest volume, or when they 

 are as full as they are to be for the season, is between the 10th and 

 20tli of July every year; not a day earlier, and not many days later. 

 After tlie 20th of July the regular system of compact, even organiza- 

 tion, breaks up. The seals then scatter out in pods or clusters, the 

 pups leading the w^ay, straying far back — the same number instantly 

 covering twice and thrice as nnuch gi-ound as they did the day or week 

 before, wlien they lay in solid masses and were marshaled on the rook- 

 ery ground proper. 



There is no more difficulty in surveying these seal margins during 

 this week or ten days in July than there is in drawing sights along and 

 around the curbs of a stone fence surrounding a field. The breeding 

 seals remain i^erf ectlj' quiet under your eyes all over the rookery, and 

 almost within your touch, everywhere on the outside of their territory 

 that you may stand or walk. The margins of massed life, as I have 

 indicated on the topographical survey's of these breeding grounds of 

 St. Paul and St. George, are as clean cut and as well defined against 

 the soil and vegetation as is the shading on my maps. There is not 

 the least difficulty in making the surveys, and in making them cor- 

 rectly. 



Now, with a knowledge of the superficial area of these breeding 

 grounds, the way is clearly open to a very interesting calculation as 

 to the number of fur seals upon them. I am well aware of the fact, 

 when I enter upon this discussion, that I can not claim j)erfect accu- 

 racy, but, as shadowing my plan of thought and method of computa- 

 tion, I propose to present every step in the processes which have guided 

 me to the result. 



Rookery space occupied by single seals. — When the adult 

 males and females, 15 or 20 of the latter to every 1 of the former, have 

 arrived ujion the rookery, I think an area a little less than 2 square 

 feet for each female maybe considered as the superficial space required 

 by each animal with regard to its size and in obedience to its habits, 

 and this limit may safely be said to be over the mark. Now, every 

 female, or cow, on this 2 square feet space doubles herself by bring- 

 ing forth her young, and in a few da3's or a week, perhaps, after its 

 birth the cow takes to the water to wash and feed, and is not back 

 on this allotted space one-fourth of the time again during the season. 

 In this way is it not clear that the females almost double their number 

 on the rookery grounds without causing the expansion of the same 

 beyond the limits that would be actually required did thej^ not bear 

 any j^oung at all'? For every 100,000 breeding seals there will be found 

 more than 85,000 females and less than 15,000 males, and in a few 

 weeks after the landing of these females thej will show for them- 

 selves; that is, for this 100,000, fully 180,000 males, females, and 

 young instead, on the same area of ground occupied previously to the 

 birth of the pups. 



It must be borne in mind that perhaps 10 or 12 per cent of the entire 

 number of females were yearlings last season and come up onto these 

 breeding grounds as virgins for the first time during this season, as 

 2-year-old cows. They, of course, bear no young. 



The males, being treble and quadruple the physical bulk of the 



