HUMPBACK WHALE. 299 



left side in the specimen described by Struthers, and tapered greatly at the free end. It is 

 loosely connected to the pelvic bone through short fibrous bands, at a point internal to the 

 outer angle of that bone. 



Appearance and Actions. 



As viewed at sea, the Humpback has several characteristics that may serve for its iden- 

 tification. As with the Rorquals, it rises to the surface, delivers its ' spout ' as the vertex of the 

 head breaks the water, then as the blowholes remain widely open for the quick inhalation, a 

 large portion of the forward part of the back appears momentarily. With the closing of the 

 blowholes, the head is depressed, and much of the back appears, sometimes quite to the dorsal 

 fin. The posterior part of the back arches shghtly as the head goes down, the dorsal fin moves 

 forward with the onward course of the body, and as it approaches the water again, the whale 

 sinks beneath the surface leaving a 'sUck' or round area of smooth water, behind. This is 

 the intermediate or surface dive of which several may be made in succession as the whale feeds 

 among the plankton currents or refreshes its lungs after a longer dive. Millais noted in one 

 individual eight, ten, and twelve of these shorter dives successively between the deeper sound- 

 ings. The longer dive differs in that the whale goes down in a nearly perpendicular course, 

 more of the posterior part of the body appears above the surface with the greater effort, and 

 the flukes of the tail finally rise clear of the water, and following the forward roUing of the 

 body, dip in nearly vertically, looking like the spread wings of a great bird as they disappear. 

 In these deeper dives the animal may be under water for a number of minutes, but in the shal- 

 low dives, for a few seconds only. Rawitz (1900) relates that one which was slightly wounded 

 by a harpoon stayed down for twenty minutes, and in a free state the long dives were of about 

 fifteen minutes duration. A pair of Humpbacks that I saw July 1, 1911, in the Atlantic, 45° 

 15' N., 37° 44' W., impressed me as being most leisurely in their surface movements. They 

 were in sight from the steamer for several moments, swimming at the surface, so as to expose 

 the entire back from the posterior part of the head to just behind the dorsal fin, which appeared 

 large and obtusely triangular. At intervals of about 15 seconds, the head was raised slightly 

 to expose the blowholes for breathing, then after the spout, the head was lowered and the whale 

 swam on slowly as before, with sometimes the entire back and dorsal fin exposed or again with 

 the top of the back only above the surface or just awash. Again they would swim along just 

 under the surface. As observed by other writers, the body is but little arched and the tail does 

 not appear during the short surface dives, but in the deeper dives, the body is much arched 

 and the flukes are thrown out as the whale goes in a nearly perpendicular course downward. 

 A remarkable series of photographs illustrating the appearance of the Pacific Humpback in its 

 dives and surface movements has been published by R. C. Andrews (1909, Plates 30-36). There 

 seems to be no definite number of spouts between the long dives. No doubt this may depend 



