THE CRESTED SEAL. 505 



grayish-white spots, which have earned for the animal the name of Leopard Seal. 

 The external ears are wanting. 



It may be observed in this place, that the situation of these organs is rather remark- 

 able. The external orifice is not placed exactly over the passage that leads to the 

 internal ear, but is situated below and a little behind the eyes, so that there is a tubu- 

 lar passage below the skin that seems to conduct the waves of sound towards the 

 hidden organs of hearing. Partly on account of this structure, and partly because the 

 Seals pass so much of their time below the surface of the water, it has been supposed 

 that the sense of hearing will be little needed by them, and that it is not at all acute. 



Yet, any one who has been accustomed to diving must have discovered that when 

 the body is entirely submerged in the water, the auditory organs are very sensitive to 

 sounds which are conveyed through the water, although not to those which are pro- 

 duced on land and are only transmitted through the upper atmosphere. For example, 

 although when a man is entirely submerged he is unable to hear the loudest shouts 

 that can be raised by persons on shore, his ears are almost painfully sensitive to any 

 sound that is produced in the water and is transmitted through its mediumship. A 

 stone thrown into the water, or a blow struck upon its surface, is heard with perfect 

 distinctness, while the measured stroke of oars and their peculiar grinding roll in the 

 rowlocks become perceptible to his ears long before the sound is audible to those who 

 are on land. 



We must be extremely cautious in offering any conjectures on the supposed efficiency 

 or dulness of certain organs because we fancy that if we were placed under the same 

 conditions our own organs would serve or fail us. In many cases these conjectural 

 assertions, among which we may reckon many of Buffon's brilliant disquisitions, are 

 found to be in direct contradiction to the real facts, and in all instances it is necessary to 

 be exceedingly cautious lest we should overlook some circumstance which may entirely 

 alter the whole aspect of affairs. 



Very little is known of the habits of the Sea Leopard, which are probably much the 

 same as those of the common Seal, as Captain Weddell, who first noticed this species, 

 speaks of it casually as a well-known animal, merely mentioning that his men caught 

 so many Leopard Seals, or that they secured so many Seal skins and so many Leopard 

 Seal skins in the course of their hunt. 



It does not appear to be a very large animal, as the average length of the largest 

 specimens is scarcely ten feet. Around the largest part of the body, the circumference 

 measures nearly six feet and a half, round the root of the tail about two feet three 

 inches, and round the neck barely two feet. It was recorded by Captain Weddell to 

 have been seen off the South Orkneys. Some specimens in the British Museum were 

 taken off the eastern coast of Polynesia. As far as is yet known, these animals are 

 only found in the Southern hemisphere. 



The CRESTED SEAL is a very curious animal, being chiefly remarkable for the sin- 

 gular structure to which it is indebted for its title. 



The head of the Crested Seal is broad, especially across the cranial region, and the 

 muzzle is very short in comparison with that of the preceding animal. The teeth are 

 also remarkable. The wonderful protuberance which decorates the head of this 

 species with a projecting crest is confined to the adult males, and even in them is not 

 always so conspicuously elevated as is represented in the figure. In the females and 

 the young of both sexes it is hardly perceptible. 



From the muzzle arises a cartilaginous crest, which rises abruptly over the head to 

 the height of six or seven inches, and is keel-shaped in the middle. This crest seems 

 to support the hood-like sac or cowl which covers the head, and is nothing but an ex- 

 traordinary development of the septum of the nose, the true nostril opening at each 

 side of it by oblong fissures. The sac is covered with short brown hair, and as it can 

 be inflated or allowed to collapse at the pleasure of the owner, it presents a very gro- 

 tesque sight. 



The real object of this appendage is not known. Some writers lean to the opinion that 

 it is intended to aid in some manner the sense of smell. This conjecture, however, seems 



