WHALES AND DOLPHINS 325 



contained the valuable substance known as spermaceti, which, although liquid in 

 the living animal, assumes the solid state after death. The ' blow-hole,' or nostril, 

 which is shaped like the sound-aperture of a violin, is situated on the top of the 

 extremity of the muzzle — a unique position among cetaceans — somewhat to one 

 side of the middle line. The relatively small eyes are situated a little distance 

 above the angle of the mouth, and the apertures of the ears form minute punctures 

 in the skin a short distance behind the eyes. Although a back -fin is wanting, a 

 series of irregular protuberances or humps occupies the middle line of the hind 

 part of the back ; the largest of these being the one in front, which is the portion first 

 to become visible when the whale rises from the water in order to breathe. The 

 inside of the mouth and the huge tongue are dazzling white ; and so is the throat, 

 which, unlike that of the Greenland whale, is of enormous capacity. The food of 

 the cachalot, which is obtained, in many instances at any rate, at very considerable 

 depths, consists mainly of gigantic cuttle-fishes and squids. The huge size of these 

 cephalopods may be estimated from the fact that wounded cachalots have been 

 known to disgorge great ' chunks ' of the arms of cuttle-fishes measuring, roughly 

 speaking, about six by six by eight feet. The diet of these whales is, however, by 

 no means restricted to food of this kind, since they also consume a considerable 

 number of surface-swimming fishes, more especially albacore and bonito. 



In this place a short digression may be made on the subject of the depth to 

 which whales are capable of diving, or 'sounding,' as it is called by whalers. 

 Formerly the belief obtained among both whalers and naturalists that when 

 whales ' sound ' they descend to enormous depths. One naturalist has estimated, 

 for instance, that the larger members of the group commonly dive to a depth of at 

 least a thousand yards, although the evidence on which this estimate rests is not 

 given. On the other hand, the naturalist to the Belgian Antarctic Expedition of 

 1897-99 has challenged this belief, and stated that, in his opinion, a hundred yards 

 is the maximum depth to which any whale can dive, and that many of them 

 cannot reach even anything like that limit. Why, indeed, it is asked, should 

 whales want to go to such depths ? All the species sound for the purpose of obtain- 

 ing food ; and in the profound darkness of a thousand yards they would be unable 

 to find food in most instances, although those which feed on animalcules might 

 perhaps obtain what they want. In regard to the species which feed on fishes 

 and cuttles, at a depth of a thousand yards they could not use their eyes to detect 

 non-luminous species, and there is no evidence that they feed on the self-luminous 

 deep-sea fish and cuttles, if there be any of the latter. On the contrary, the 

 available evidence indicates that they feed on ordinary light-dwelling fishes and 

 cuttles which live in much shallower zones. Moreover, it is known that the 

 effects of a pressure of more than three atmospheres prove fatal to human life, 

 -and although it may be urged that whales can stand treble this pressure, or nine 

 atmospheres, which would occur at about ninety yards depth, it is inconceivable 

 that they could resist the effect of ten times the latter pressure, or ninety atmospheres. 

 Again, it seems impossible that a whale, whose body is only slightly heavier than 

 water at ordinary pressure, could exert the muscular force necessary to propel that 

 body to a depth of a thousand yards. Whether the same naturalist has so strong a 

 case in his contention that whales never sleep, must await further consideration. 



