262 



DISCOVERY REPORTS 



BREEDING HABITS 



As might reasonably be expected from the sohtary habit of this animal, information 

 regarding its breeding is scarce. From the previous section it appears that the ovaries 

 of cows killed in the first three months of the year are active, and the only month in 

 which I have seen leopard seals keeping company is February, when as many as three 

 were observed swimming together. Wild's description (1923) of a "fight" when one 

 seal was seen to leap repeatedly from the water to a height of 6 ft. was much more 

 likely to be a record of courtship. The date was 9 February. 



The cow, S.S. i, killed on 18 January had a single corpus luteum and no trace of 

 others, so that this was probably the first ovulation of the season. Bertram's no. 142 

 of 27 January has four corpora lutea in the two ovaries, the largest being 30 mm. in 

 longest diameter and the other three in difTerent stages of degeneration, and his seal 

 no. 144 has a corpus luteum in each ovary. I consider that it may be safely assumed that 

 the first two months of the year, and perhaps the third as well, are the season of mating, 

 and from the evidence of the ovaries it is highly probable that this species ovulates 

 several times at short intervals. Additional evidence of a rather prolonged mating 

 season is supplied by records of foetuses. On 16 February a foetus of 16 mm. was 

 obtained by the Discovery Committee's stafT, and in late February 1921 I found foetuses 

 about 30 mm. Bertram records the following in March and April : 



Table IX 



It will be observed that within nine days there were collected foetuses of 42, 112 

 and 250 mm., and that for March there is recorded a foetus of 118 mm., nearly three 

 times the length of one secured five days later (no. i loi, 42 mm.), this difference being 

 analogous to that of human foetuses of four and two and a half months. 



Records of newly born pups are very scarce. Bruce states that in the South Orkney 

 Islands only one was seen, but not secured, in November; Matthews saw one about 

 107 cm. in September, and the specimen in the British Museum was killed, according to 

 the label, at Christmas. The extended pupping season implied by these observations is 

 quite in keeping with the prolonged mating season suggested above (January to 

 March). It follows that the period of gestation is about eight months. Since females 



