THE SOUTHERN SEA LION 279 



Second year (about eighteen months). Males 135-7 cm., g specimens; females 

 118-5 '^'T^-' 3 specimens. The rate of growth has slowed to 13 per cent in the males 

 and 5 per cent in the females. Both sexes are much more slender compared with their 

 body length than in the previous year; they seem to lose condition a good deal when 

 they cease sucking. 



Third year (about thirty months). Males 152-4 cm., 5 specimens; females 125 cm., 

 4 specimens. The rate of growth in each sex is about the same as in the previous year. 



Fourth year (about forty-two months). Males 173 cm., 5 specimens; females 143 cm., 

 4 specimens. The rate of growth is 13 per cent for males and 14 per cent for females. 



Fifth year (about fifty-four months). Males 211 cm., 4 specimens; females 156 cm., 

 3 specimens. The rate of growth in the males shows a further increase, to 22 per cent, 

 some of this stage reaching the size of the small adult males. In the females the rate 

 of growth appears to drop to 9 per cent, a decrease which, if it really occurs, is perhaps 

 associated with the onset of sexual activity. 



Sixth year and upivards. Adult males, 234 cm., 9 specimens; adult females, 179 cm., 

 II specimens. The rates of growth are 11 and 15 per cent respectively for males and 

 females (Figs. 3, 4). 



COLOUR 



At first sight a herd of sea lions appears to be uniformly brown in colour, but on 

 closer inspection the colour is seen to be very variable. 



In the adult males the darker colours predominate; the following list is arranged in 

 order of frequency : 



(i) Dark brown all over, mane sometimes paler. 



(2) Very dark brown, almost black, mane dull yellow. 



(3) Grey, often with a slight greenish cast, mane pale. 



(4) Very pale gold all over. 



Except in phase 4 the belly is always dark yellow and the hair of the flippers reddish. 

 Phase I is the commonest, as is indicated, and 2 and 3 are frequent. Phase 4 is extremely 

 rare: I have seen only one specimen, but no doubt others exist since a corresponding 

 colour in cows has been seen on a number of occasions. 



The "mane" covers the top of the head and the neck, and is thickest at the back 

 and thinnest at the front. 



The adult cows may be divided into five groups : 



(i) Dark brown, with the back of the head and neck dull yellow, face dark. 



(2) Dark brown with the whole head and neck yellow, muzzle dark. 



(3) Very dark brown, usually with a paler colour at the muzzle. 



(4) Dull yellow all over, face dark. 



(5) Pale cream all over, face dark. 



All these phases are quite common except the last. Except in phase 5 the belly of 

 the female is of much the same dark yellow as that of the male. 



