168 THE FUR SEALS OF THE PRIBILOF ISLANDS. 
The explanation of this condition of things is that on the rookeries of St. George 
the blue foxes,! of which there are many, had eaten all the pup carcasses without 
exception. The final count had to be made simply by skulls, or spinal colums, or such 
parts of the animals as could be positively identified. 
RECONSTRUCTION OF ST. GEORGE ESTIMATES. 
It is unnecessary to remark that these figures for St. George can not be used as 
they stand. Some sort of estimate must be made to take their place. No fairer basis 
for such an estimate exists than to apply to the rookeries of St. George the ratio of 
dead pups found in October on St. Paul. On this island the ratio of dead pups found 
in October to the total number estimated to have been born was 11.19 per cent.? This 
would necessitate the addition of 1,362 pups to make the conditions of St. George 
comparable with those on St. Paul. This amount, together with 150 pups which were 
removed from the rookeries of both islands during the breeding season for purposes 
of dissection, makes the total death rate subsequent to the middle of August, and 
directly chargeable to starvation, aggregate 16,019.° 
THE DETAILED ESTIMATE. 
This total, as will be seen by the explanations already given, is not entirely 
satisfactory, but itis a real one so far as it goes, and fully 12,000 of itis an actual count, 
1In Mr. Macoun’s report for 1896 this undoubted fact, which he saw with his own eyes, is 
needlessly questioned. If the foxes, as was the fact, had completely destroyed the 897 carcasses 
which he counted, it is begging the question to assume, as he does, that they, aided by the elements, 
could not have destroyed the 1,362 additional pups necessary to make the conditions of St. George 
agree with those of St. Paul. 
2 This percentage is computed on the original census of 1896, not on the revised figures substituted 
in 1897. 
“A strong effort has been made by Professor Thompson and by Mr. Macoun in their reports of 
1896 to weaken the force of these definite results regarding the starvation of pups. Not finding it 
possible to deny the fact of starvation or its importance, they have endeavored to minimize its effects 
by insisting that the causes of early mortality continued into and were at work in the period of 
starvation. Nothing could be more misleading than this. The early causes of death are Uncinaria, 
trampling, starvation through early separation from the mother, drowning, accidents. All these 
have to do with the weakness and helplessness of the very young pups, and must necessarily cease 
with the close of the breeding season. The pups die from or outgrow the worm before September 1. 
In fact, this cause is practically inoperative after August 20. Pups are only trampled in the first few 
days after birth, and they are only lost from their mothers, if at all, at this time. They certainly do 
not drown after they have learned to swim, which they do by the middle of August. The period of 
death from starvation lasts from August 15 to October 20. The causes of the early and later mortality 
were absolutely distinct, and that the latter was due practically without exception to starvation 
needs no demonstration to those who made the count of the dead and dying pups on the rookeries of 
St Paul in October, 1896. 
