1899] THE HABITS OF THE NORTHERN FUR SEAL 29 
water. On its termination the animals swam away in different 
directions. 
On the 30th June the bull whose harem is numbered II. in the 
table on p. 25, was observed im coitw twice during the space of about 
one hour, the first time at about 6.54 p.m. He was afterwards active 
until about 7.33 P.M., when he again performed the act. 
On the 1st July the same bull was observed in coitw twice during 
a period of six hours, that is to say, at 12.9 pM. to 12.14 pM. and 
again at 12.33 p.m. until 12.415 pM. 
On the 2nd July he was observed im coitu four times during a 
period of four hours, viz. at 12.55 p.m. until 12.374 pM. at 1.30 pM. 
until 1.355 p.m, at 2.5 p.m. until 2.12 p.m. (in the latter case apparently 
futilely), and at 3.31 p.m. to 3.394 P.M. 
During a period of thirteen hours, in which on various occasions the 
two bulls were under observation, each was observed in coitu eight 
times. 
If each bull kept up the same rate during a whole month of 
twenty-eight days, it is obvious that he could accommodate a harem of 
over 200 cows. The rate is, however, as shown by the above notes, 
not constant, and it happened that the periods of greatest activity of 
the two animals did not always coincide. This I put down to the 
varied times at which the cows came into heat, and from the notes which 
I was able to make it seems nearly certain that the cows are covered 
more than once each. ‘The action of bull 1 during six hours, in 
which he was observed in coitw no less than six times, led me to 
believe that, in the ease of several at least of the acts which I then 
observed, it was the same cow which was covered; but of this I cannot 
be certain, it being extremely difficult to keep any one cow under obser- 
vation in a crowded harem. 
On the South rookery of Bering’s Island the two bulls are known 
to have been present from about the 5th July to the 1st August, a 
period of only about twenty-six days. Their departure at about the 
latter date may be assumed to have been due to either of two facts— 
viz. either there were then no females requiring their services, or else 
their power of accommodating the females was finished for the season. 
That the latter was the true reason seems almost certain, from the fact 
that there was a newly-born pup with its mother—probably a three- 
year-old cow with her first pup—on the rookery beach when I visited 
it on the 2nd August, and also from the fact that it is in the last week 
in July or the first week in August that the large old bulls of the 
Copper Island rookeries leave their harems and retire to the beaches 
north and south of the breeding-grounds and elsewhere. 
We know that these two bulls at the South rookery had between 
them a lot of at least 530 cows, or 265 cows each. If each of these 
cows were covered only once during the twenty-six days, it would be 
necessary for each bull to satisfy about ten cows every twenty-four 
