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SEXUAL selection: mammals. 
Part II. 
posed by some writers to affect the voice. The nose of 
the male sea-elephant (Macrorhinus joroboscideus), Avhen 
about three years old, is greatly elongated during the 
breeding-season, and can then be erected. In this state 
it is sometimes a foot in length. The female at no 
period of life is thus provided, and her voice is dif- 
ferent. That of the male consists of a wild, hoarse, 
gurgling noise, which is audible at a great distance, 
and is believed to be strengthened by the proboscis. 
Lesson compares the erection of the proboscis, to the 
swelling of the wattles of male gallinaceous birds, whilst 
they court the females. In another allied kind of seal, 
namely, the bladder-nose {Cystophora cristata), the head 
is covered by a great hood or bladder. This is inter- 
nally supported by the septum of the nose, which is 
produced far backwards and rises into a crest seven 
inches in height. The hood is clothed with short hair, 
and is muscular ; it can be inflated until it more than 
equals the whole head in size ! The males when rut- 
ting fight furiously on the ice, and their roaring ^^is 
said to be sometimes so loud as to be heard four 
miles off.” When attacked by man they likewise roar 
or bellow ; and whenever irritated the bladder is in- 
flated. Some naturalists believe that the voice is thus 
strengthened, but various other uses have been assigned 
to this extraordinary structure. Mr. E. Brown thinks 
that it serves as a protection against accidents of all 
kinds. This latter view is not probable, if what the 
sealers have long maintained is correct, namely, that 
the hood or bladder is very poorly developed in the 
females and in the males whilst young.^ 
^ On the sea-elephant, see an article by Lesson, in ‘Diet. Class. 
Hist. Nat.^ tom. xiii. p. 418. For the Cystophora or Stemmatopus, see 
Dr. Dekay, ‘Annals of Lyceum of Nat. Hist. New York,’ vol. i. 1824, 
p. 94. Pennant has also collected information from the sealers on this 
