1883.1 on Whales, Past and Present, and their Probable Origin, 371 



more remarkable. In all known Cetaeea (unless Platanisia be really 

 an exception) a pair of slender bones are found suspended a short 

 distance below the vertebral column, but not attached to it, about the 

 part where the body and the tail join. In museum skeletons these 

 bones are often not seen, as, unless special care has been taken in the 

 preparation, they are apt to get lost. They are, however, of much 

 importance and interest, as their relations to surrounding parts show 

 that they are the rudimentary representatives of the pelvic or hip 

 bones, which in other mammals play such an important part in con- 

 necting the hind-limbs with the rest of the skeleton. The pelvic arch 

 is thus almost univers;\lly present, but of the limb proper there is, as 

 far as is yet known, not a vestige in any of the large group of toothed 

 whales, not even in the gre^it Cachalot or Sj>erm "Whale, although it 

 should be mentioned that it has never been looked for in that animal 

 with any sort of care. With the Whalebone Whales, however, at 

 least to some of the species, the c^^se is different. In these animals 

 there are found, attached to the outer and lower side of the pelvic 

 bone, other elements, bonv or onlv cartila urinous as the case mav be, 

 cleaily representing rudiments of the tirst and in some cases the 

 second segment of the limb, the thigh or femur, and the leg or tibia. 

 In the sm;\ll BahTuoptera rostrata a few thin fragments of cartilage, 

 imbedded in tibrous tissue attached to the side of the pelvic lx>ne, con- 

 stitute the most rudimentai-y possible condition of a hind-limb, and 

 could not be recognised as such but for their analogy with other aUiovl 

 cases. In the lai-ge Korqual. Bahrnopftra musculus, 67 feet long, pre- 

 viously spoken of, I was fortunate emmgh in 1865 to find attached 

 by tibrous tissue to the side of the pelvic bone (which was sixteen 

 inches in leni:i;th) a distinct femur, consistinix of a nodule of cartilaire 

 of a slightly compressed, irregularly oval form, and not quite one 

 inch and a half in length. Other specimens of the same animal 

 dissecteti by Tan Beneden and Professor Struthers have shown the 

 same ; in one case, partial ossification had taken place. In the genus 

 Meijapftra a similar femur has been described by Eschricht ; and the 

 observations of l\eiuhardt have shown that the Greenland Eight 

 Whale [Bahrna mysiiceius) has not only a representative of the femur 

 develojvd far more completely than in the Konj^ual, being from six 

 to eight inches in length and completely ossified, but also a second 

 smaller and more irreguhu-ly formed Ixme, representing the tibia. 

 Our knowledge of these p\rts in this species has recently been 

 greatly extended by the resciirches of Pr. Struthers, who hiis pulv 

 lished in the " Journal of Anatomy ' for 1881 a most c;uvful and 

 dotaikxl account of the dissection of seven\l specimens, showing the 

 amount of variation to which these bones i^as with most rudimentary 

 structuivs) aiv liable in different individuals, and describing for the 

 tirst time their distinct articulation one with the other by synovial 

 joints and capsular ligaments, and also the most renuu-kable juid 

 unhx^ked-for presence of muscles passing fivm one lK>ue to the other, 

 representing the adductors and dexoi*s of miunmals with completolv 



