THE RUSSIAN FUK-SEAL ISLANDS. 63 



TTnited States Fish (Jomniissioii have brought out correctly tlie main fiicts relatins' to 

 the life-history of the seals. 



We have frequently seen, however, that the various exc^eptions alluded to have 

 been brought forward in the controversies relating to this theme as particularity 

 essential, thus obscuring the main questions, while, on the other hand, conditions have 

 l)eeu described and depicted as so uniform and stable that it has been easy for the 

 oiiposite side to controvert these assertions, thus throwing doubt upon the correctness 

 of the whole argument and the soundness of the conclusions. It may be useful, 

 therefore, to review a few of these questions. 



A protracted stay at the rookeries reveals two facts. The one which probably 

 lirst impresses the observer is the curious stability of the general outline of the 

 groups of breeding seals, especially if the comparisons be made at frequent intervals 

 during the earlier part of the season. The masses of seals assume certain definite 

 shapes which in many cases have no apparent relation to the nature of the ground 

 upon which they are lying. Thus, on the North Reef Bookery on Bering Island, a 

 very peculiar feature of the distribution of the breeding seals this summer was a 

 narrow band of seals which extended obliquely across the northern end of the 

 "parade-grounds," cutting off from the latter a small oval ijortion, visible in most of the 

 l)hotographs (plates 19, 21, 22) and also indicated in the map (plate S), and connecting 

 the masses of seals on the western side of the reef with those on the eastern side. 

 I have walked over the territory thus curiously occnpied many a time, but 1 have 

 failed to find any difference in the ground which will account for this belt or answ(>r 

 the question why the seals do not also occupy the bare oval island it surrouiuls. 



To appreciiite this (jcnernl stability of the outline, it is necessary to have had an 

 oi)portunity to observe the rookery for some length of time. A person who had only 

 a iew days at his disposal for examining the same rookery might, on the other hand, 

 be impressed by the fact that on two different days, or at different hours of the same 

 day, the outlines thus referred to present entirely different aspects, and if he offered 

 photographs in evidence of tliis fact he might seemingly prove the instability of these 

 lines. Thus, the "baiul" of seals on the North Reef Kookery above alluded to did 

 occasionally entirely disappear, particularly during the warmer portion of bright, 

 sunny diiys, or after the rookery had been disturbed by a recent drive (see pi. 20). 



Nevertheless, this "band" was a very chdracferistic feature of the seals on that 

 rookery. Single photographs are therefore of no ])articnlar value for comparison from 

 year to j/ear unless they arc taken by a person familiar irith the charaeteristic (Jisfribiitiun 

 and the pieir is selcrted by him for that partienlar purpose. The main reliance must, 

 therefore, be placed upon the observer, and his statements must be received in 

 accordance with his known exjjerience, accuracy, and intelligence. 



PROPORTIONATE NUMBER OF SEXES AND AGES ON ROOKERIES. 



A question which of late has been given considerable prominence is that of the 

 relative number of breeding females and old bulls on the rookeries. Upon this, and 

 M|)on the closely connected one as to the number of females a bull is able to serve, 

 there has been a great diversity of opinion.' My experience this summer leads me to 



'While maintaining that the valne of the gnesses as to the nnnil)er of females a bull is able to 

 serve is of necessity very ilnliioiis, I may mention that Mr. Kluge, who for eight years spent the summer 

 upon Tiulini Island with the seals pr;ictieallv umli-r his very eyes the whole season, informed me tliis 

 summer that " lie does not for a moment believe that twenty-tivo females to a bull are in the least too 

 many," though he did not venture to guess at the maximum. 



