October 27, 1916] 



SCIENCE 



609 



passed its first stage of complete suspension of 

 killing 1 , but it will go on for nine further 

 years adding 4,000 unnecessary reserve bulls 

 annually. 



The harmful effect of this abnormal state of 

 affairs is already beginning to be evident. 

 Preliminary information regarding the condi- 

 tions found in 1916 show a total of 3,500 

 harems on the Pribilof Island rookeries. In 

 other words, while there has been a gain of 

 about 25 per cent, in the stock of breeding 

 females since 1912, there has been a gain of 

 about 150 per cent, in breeding males. This 

 is due to the pressure of idle bulls upon the 

 breeding herd. The increase in this class of 

 animals since 1912 is 2,280 per cent. These 

 animals crowd into the massed rookery por- 

 tions and establish small harems by capture, 

 and their attempts to hold and augment these 

 harems keep the breeding grounds in a con- 

 stant turmoil to the injury of the mother seals 

 and the trampling of their young. This condi- 

 tion will grow steadily worse as the young 

 males now being released from killing grow 

 to maturity. 



More important still is the obscurity which 

 this increasingly abnormal condition will 

 throw over the vital facts of the herd — its 

 normal rate of increase and the proper pro- 

 portion of male life — which a prolongation of 

 the normal condition of the last six or eight 

 years, throughout the early stages of the 

 herd's recuperation, would have cleared up. 

 On this subject I may quote the following 

 paragraph from my report to the Bureau of 

 Fisheries in 1913 : 



Unfortunately, if the suspension of land killing 

 is prolonged, the balance will be broken. The 

 herd will begin at once to enter upon a new era 

 of abnormal conditions (like those of 1896-97). 

 The pressure of the idle bulls will increase the 

 number of harems without reference to increase in 

 cows and the averages (resulting from the counts 

 of pups) will become useless. The mortality 

 among the cows and pups will increase fright- 

 fully, retarding the development of the herd. The 

 work of rookery inspection and investigation will 

 be rendered difficult and dangerous. The hand- 

 ling of the bachelor seals on the killing fields will 

 also be attended with difficulty and danger by 



reason of the bulls which will necessarily be taken 

 up in driving. Hauling grounds and breeding 

 grounds will be overrun by a horde of savage, 

 fighting bulls. The herd will go into eclipse and 

 it will be fifteen or twenty years before it 

 emerges from the darkness and begins to show 

 normal conditions again. Its size will then pre- 

 clude the possibility of counts or accurate esti- 

 mates to enable those in charge to find a basis of 

 understanding the herd such as we have to-day. 



The condition thus warned against is now 

 practically inevitable. The department of 

 commerce, by accepting as " wise and sound 

 legislation" the fur-seal law of 1912 and 

 taking no step towards its repeal or amend- 

 ment, has deliberately thrown away the oppor- 

 tunity to settle the two important facts vital 

 to the future administration of the fur-seal 

 herd. George Archibald Clark 



Stanford University, Calif., 

 September 19, 1916 



IS DYNAMICS A PHYSICAL SCIENCE? 



Professor Huntington's latest communica- 

 tion 1 helps to make clear the difference be- 

 tween his method of treating mass and the 

 usual treatment. According to the ordinary 

 view, such problems as the one proposed by me 

 are solved very simply by the principle that 

 the mass of a tody is the sum of the masses of 

 its parts. Although Professor Huntington 

 does not give a general 2 solution, he indicates 

 that his method also makes use of this prin- 

 ciple of additivity, but only after it has been 

 proved by an analysis involving internal 

 forces, the law of action and reaction and the 

 law of vector composition of forces.. Appar- 

 ently he is unwilling to assume as funda- 

 mental even the fact that the mass of a body 

 is increased by adding matter to it. I have 

 no logical objection to this procedure, but it 

 seems to me to be an unnecessarily difficult 

 method of introducing a very simple principle. 

 It is to be noted, moreover, that the proof of 



i Science, September 8, 1916. 



- The general solution must cover any case what- 

 ever in which a body is formed by putting to- 

 gether the material of two bodies; for example, 

 the case of a body formed by fusing together two 

 lumps of metal. 



