COLOR VARIATIONS IN THE FUR SEAL. 5 



The throat of the male becomes gray at au earlier age — 4 or 5 years — than does 

 that of the female, and at the same time the belly becomes ashy, the junction of the 

 back pelage with that of the under side being marked by a lighter chestnut-tinged 

 line. 



At the age of 6 or 7 years the males are an almost uniform dark gray, with the 

 hairs of the top of the head and neck considerably longer than that of the rest of tlie 

 body. 



There seems to be some variation in the color of the older rookery bulls — those 

 7 years old and upward — some animals being of a rich seal brown, washed with yel- 

 lowish-white on the neck arid shoulders 5 others with a distinct reddish or yellowish 

 cast. 



Close examination, however, shows that even the darkest animals are more or 

 less grizzled, and the reddish coloration is undoubtedly largely due to the length of 

 time that the animal has been on land and undergone the bleaching effect of light and 

 partial drying. 



This change of color — due to exposure, and in a measure to dirt — is most notice- 

 able among the females, those which have been longest out of water having a brown, 

 sunburned appearance. The amount of dirt naturally varies according to the rookery, 

 and is in some cases very noticeable when a female plunges into the wash of the surf, 

 leaving a trail of muddy water behind. Still this explanation is ndt wholly satis- 

 factory, and there is a certain amount of color variation which seems to be individual 

 and not to be accounted for on the scor^ of age. 



The gray bulls seen here and there on the breeding grounds are either compara- 

 tively young animals which have been able to take and hold a place on the rookery, 

 or cases where the assumption of the dark color of the adult has bei'u delayed, or for 

 some cause failed to take place. It is probable that the lightest colored males are 

 those in this last condition, in which age manifests itself by a general lightening in 

 the color of the coat. 



As among birds, some seals undergo their color changes much more rapidly than 

 others, and this results in occasionally finding a young female with the colors of old 

 age, or old females with the light gray and white of the fresh 2-year-olds; these 

 females are very noticeable among the other darker-colored females. As is only 

 natural where individuals are so numerous, cases of albinism are occasionally noted, 

 some being quite complete and others only partial. Oue or two pups have been taken 

 of a yellowish color, with pink eyes and pale flippers, but no adult albino has been 

 noted, the nearest approach to it being a cow of a yellowish cast seen on Lukanin, 

 and another mottled with yellowish seen on Tolstoi. 



The accompanying tables of measurements and weights may be considered as 

 representing good average specimens of their respective classes. The weights of the 

 two fetal specimens of April 22 were taken from nearly dry alcoholics, which were by 

 no means so heavy as the fresh specimens would have been, so that 3J and 4J pounds 

 would be well within the mark. The fetus at term is one of several obtained from 

 dead cows on St. Paul and is a good average example, for while now and then a pup 

 is seen noticeably below the others in size, none was measured less than 22 inches 

 long. The measurements and weights of newly born pups given by Elliott are 

 worthless. Save for his brown color, the young fetal seal is much like the adult, 

 being well formed and well proportioned, the head not having the disproportionate 



