1162 THE NATIONAL GEOGRAPHIC MAGAZINE 
Photo by Walter I. Lembkey, U. S. Bureau of Fisheries 
A MOTHER SEAL AND HER NEW-BORN PUP (SEE PAGE 1145) 
After the second year each cow seal bears one pup annually for a period of probably 
ten years. The fur-seal pup from its birth until it leaves the islands in winter is nourished 
exclusively on milk. The killing of the mother seals while at sea, where they are obliged to 
go for food, therefore results in the death of their pups by slow starvation, and is a most 
serious injury to the herd from the loss of the potential productivity of the cows in subse- 
quent years, 
