192 ALLEN: NEW ENGLAND WHALEBONE WHALES. 



Accepting Kiikenthal's conclusion that the vestigial phalanges occasionally found in 

 embryo Fin Whales between the second and third fingers, really represent the lost third digit, 

 it results that the functional fingers correspond to digits I, II, IV, and V of the typical verte- 

 brate hand. These consist each of a basal segment or metacarpal, succeeded by several bony 

 or cartilaginous phalanges, the exact number of which varies somewhat, partly from the fact 

 that in immature specimens they are not wholly bony. In the respective digits the number 

 of these phalanges is given by Struthers as 4, 7, 7, 4 in an aged individual. The Gloucester 

 specimen had 4, 6, 4, 2 on one side and 4, 6, 5, 2 on the other according to Dwight. In True's 

 (1904, p. 143) table summarizing observations of several investigators, it is shown that for 

 digit I, 3 or 4 is usual, rarely 2; for digit II, 6 is usual, rarely 5 or 7; for digit IV, rarely 4, 

 usually 5, sometimes 6 or 7; for digit V usually 3, sometimes 2 or 4. Digits 2 and 4 have 

 therefore regularly more than the usual three phalanges, a condition known as ' hyperphalangy.' 



The hind limb is not present in the adult whale, yet in very small embryos its rudiment 

 may be seen in the shape of a small papilla on each side of the anus. It does not develop, 

 however, and must have been lost very long ago in the history of the race. The pelvic girdle 

 likewise is poorly developed and is represented in the adult by two bones, situated one on each 

 side imbedded in the flesh above the anus. They are somewhat triangular in form with an 

 inner crescentic outline, and externally a large projection near one end, corresponding to the 

 pubic element. They are supposed to represent each a half of the pelvis with the elements 

 much reduced. That they have not wholly disappeared is probably because they still sub- 

 serve a slight function for muscle attachment. On the lower and external side, held by liga- 

 ments on the curve between the pubis and ilium (or the points corresponding to these elements) 

 is a small round nodule of bone which represents all that is left of the head of the femur. The 

 size of the pelvic bones varies more or less. In the Society's specimen, which is an immature 

 female, they are 8.5 and 9 inches long respectively but may be as long as 23 inches (Struthers) 

 in an adult male, with a femoral nodule two inches long. 



Movements and Spouting. 



The actions and appearance of living Finbacks are somewhat characteristic, though it 

 is not probable that the larger species of Balaenoptera can always be identified at sea. The 

 first photographs published showing living Finbacks in the North Atlantic, are those of True 

 (1903). Millais has also published a figure showing the spout of this whale, and Andrews 

 (1909) has given an excellent series of photographs illustrating the spouting and other move- 

 ments of the Pacific Finback (B. velifera}, a very closely allied species. One's first view of 

 a whale at sea is apt to be extremely disappointing, for instead of a huge bulk floating lightly 

 on the surface, as pictured in the books of childhood, a very small portion only of the great 



