104 



NATURAL HISTOEY OF AQUATIC ANIMALS. 



growing longitudinally in the first two; after she has passed her fourth and fifth years, she weighs 

 from thirty to fifty pounds more than she did in the days of her youthful maternity. 



The male does not get his full growth and weight until the close of his seventh year, but 

 realizes most of it, osteologically speaking, by the end of the fifth ; and from this it may be 

 perhaps truly inferred, that the male Seals live to an average ago of eighteen or twenty years, 

 if undisturbed in a normal condition, and that the females attain ten or twelve seasons under the 

 same favorable circumstances. Their respective weights, when fully mature and fat in the spring, 

 will, in regard to the male, strike an average of from four to five hundred pounds, while the 

 females will show a mean of from seventy to eighty pounds. 



I did not permit myself to fall into error in estimating this matter of weight, because I early 

 found that the apparent huge bulk of a sea-lion bull or fur-seal male, when placed upon the 

 scales, shrank far below my notions : I took a great deal of pains, on several occasions, during the 

 killing season, to have a platform scale carted out into the field, and as the Seals were knocked 

 down, and before they were bled, I had them carefully weighed, constructing the following table 

 from my observations : 



Table showing the weight, size, and growth of the Fur Seal [Callorhinus ursinus), from the pup to the 



adult, male and female. 



Age. 



Kemarks. 



One week 



Six months 



■ One year 



Two years 



Threo years 



Four years 



Five years 



Six years 



Eight to twenty 

 years. 



A male and female, being the only ones of the class handled, June 20, 1873. 



A mean of ten examples, males and females, alike in size, November 28, 1872. 



A mean of six examples, males and females, alike in size, July 14, 1873. 



A mean of thirty examples, all males, July 24, 1873. 



A mean of thirty-two examples, all males, July 24, 1873. 



A mean of ten examples, all males, July 24, 1873. 



A mean of five examples, all males, July 24, 1873. 



A mean of three examples, all males, July 24, 3873. 



An estimate only, calculating on their weight when fat, and early in the season. 



Weight of female Seals.— The adult females will correspond with the three-year-old 

 males in the above table, the younger cows weighing frequently only seventy- five pounds, and 

 many of the older ones going as high as one hundred and twenty, but an average of eighty to 

 eighty-five pounds is the rule. Those specimens of the females which I have weighed were 

 examples taken by me for transmission to the Smithsonian Institution, otherwise I should not 

 have been permitted to make this record of their weight, inasmuch as weighing them means to 

 kill them; and the law and the habit, or rather the prejudice of the entire comniunity up there, is 

 unanimously in opposition to any such proceeding, for they never touch females here, and never 

 set their foot on or near the breeding-grounds on such an errand. It will be noticed, also, that I 

 have no statement of the weights of those exceedingly fat and heavy males which first appear on 

 the breeding-grounds in the spring; those which I have referred to, in the table above given, were 

 very much heavier at the time of their first appearance in May and June, than at the moment 

 when they were in my hands, in July; but the cows, in the other class, do not sustain protracted 

 fasting, and therefore their weights may be considered substantially the same throughout the year. 



Change in weight.— Thus, from the fact that all the young Seals and females do not change 

 much in weight from the time of their first coming out in the spring, till that of their leaving in 

 the fall and early winter, I feel safe in saying that they feed at irregular but not long intervals, 



