KEPOET OF AMEEICAN COMMISSIONERS. 349 



many animals, the number of offspring thrown Effect of a single 



•^ X o youug a year. 



upon the world to take their chance in the 

 struggle for existence is small, each fertile 

 animal giving birth to only a single young each 

 year. 



The life of the seal herd, then, depending as it How hirth-rate 



may be lessened. 



unquestionably does on the constancy of the 

 number of births, can be endangered from two 

 directions: First, from the killing of fertile 

 females ; and, second, from the excessive killing 

 of males, carried to such an extent as to prevent 

 the presence of the necessary number of virile 

 males on the breeding rookeries. To one or the 

 other of these causes must be charged the great 

 change that has come upon the rookeries within 

 recent years, and the commercial destruction 

 wdth which the sealing industry is now seri- 

 ously threatened. 



We are firmly of the opinion that an impartial Killing a cer- 



■^ -■■ ^ taiu number oi 



examination of all the facts in the case will show ^^^''f , .""V}^ ""*^ 



aticet birtn-rate. 



conclusively that the latter of the two possible 

 causes haa^ had no appreciable part in the de- 

 structive work that has been accomplished. 



The polygamous habits of the fur-seal have Battles on rook- 

 eries show no lack 



already been described, as well as the separation ^^ males, 

 in hauling out of the 'holluschickie' or younger 

 males from the breeding rookeries. The battles 

 among the older males for places upon the breed- 



