ZOOLOGY: G. H. PARKER 
169 
TABLE 1 
Numerical Statement of the Condition of the Alaskan Fur Seal Herd from 1912 
to 1917 Inclusive 
YEAR 
PUPS 
HAREM BULLS 
AVERAGE HAREM 
IDLE BULLS 
ESTIMATED 
TOTAL HERD 
1912 
81,984 
1,358 
60.4 
113 
215,738 
1913 
92,269 
1,403 
65.8 
105 
268,305 
1914 
93,250 
1,559 
59.8 
172 
294,687 
1915 
103,527 
2,151 
48.1 
673 
363,872 
1916 
116,977 
3,500 
33.4 
2,632 
417,281 
1917 
128,024 
4,850 
26.4 
11,683 
468,692 
thousands. Here it will be seen that the successive counts, with the excep- 
tion of one, lie almost exactly on a curve such as would describe the com- 
mencement of an autocatalytic process. This type of curve when complete 
shows in the beginning an accelerated increase, after which it approximates 
more nearly to a uniform rate till a decline of this rate sets in due to a check- 
ing of autocatalysis by retarding factors. The decline ceases when auto- 
catalysis is balanced by the conditions unfavorable to it. This form of 
curve is usually applied to the growth of an individual, but there is no reason 
why it should not apply also to the growth of a population, which after all is 
protoplasmic growth and hence dependent upon autocatalysis. It is, there- 
fore, not surprising to find that the increase in pups should follow a curve 
characteristic of such a process. The period of accelerated increase, as 
Graph 1 shows, extended from 1912 to 1914 or 1915. The period over which 
a more nearly uniform rate of increase was maintained began in 1914 or 1915 
and extended to the last reported count, 1917. How much longer it will 
continue cannot be stated. Eventually, as numbers augment, the beaches 
on which the breeding occurs will become overcrowded, shortage of food may 
supervene, epidemics due to unfavorable conditions may appear, and these 
and other like influences will cut down the rate of increase until the herd, 
having arrived at its maximum number, will stand at a constant level. Just 
as it is impossible to predict how long after 1917 the steady increase will be 
maintained, so also it is impossible to foretell when equilibrium will be reached. 
The only pup count that fails to fall in line with the interpretation of the 
growth of the herd just given is that of 1913. This count when considered in 
relation to the other counts is some six thousands too high. When the pup 
census of 1914 was made public, it was pointed out (Osgood, Preble, and 
Parker, 1915, p. 41) that the increase of this year over the preceding one was 
very slight, as a matter of fact only a little over 1%, whereas the increase 
of 1913 over 1912 had been 12.5%. Clark (1916, p. 608) also commented 
critically on these numbers and stated that "The results gave a gain of only 
1%, without any adequate explanation for the irregularity," the implication 
being that the count of 1914 was deficient. Now that there are in all six 
counts that may be compared, it is quite obvious, as an inspection of Graph 
