^8 



confluent and soldered together, as it were, into one bone, that it 

 is more difficult to distinguish them from each other than 

 perhaps in any other cetacean, although the soldering of all the 

 seven cervical vertebrae into one piece occurs not unfrequently 

 among the dolphins. 



In this sublunary creation, every organic structure passes off 

 gradually to some other one ; and it is in consequence of this law 

 of nature that almost all characters, however distinctive of groups 

 they may appear on a first glance, will be found to give way at 

 some point or other of any series which forms a group. Few 

 characters, for instance, can more generally denote the class of 

 Mammalia than their seven cervical vertebrae. The atlas, the 

 axis, and the five others are all to be seen distinct in the 

 dolphin of the Ganges, as well as in the swan-like neck of the 

 cameleopard. Among the sloths, however, we find one species 

 with nine cervical vertebrae, and on the other hand among Cetacea 

 we often see their seven cervical vertebrae soldered together into 

 one. The sperm whale, or Catodon, as we have seen, has its atlas 

 distinct, but its axis and the following five vertebrae are soldered 

 together into one piece. "When a character of this kind breaks 

 down, it becomes, from its tendency to vary, of little more value 

 than to distinguish species. Thus Delpliinus delpliis, D. glohiceps, 

 D. griseus, and Plioccena communis, as also the genus Hyperoodon, 

 have all the cervical vertebra? soldered together. Delpliinus 

 Tursio has them all distinct, as well as the Platanista or Del- 

 pliinus Gangetiott,s, Linn. In the Cape Eorqual the atlas is distinct, 

 and also the four last vertebra?, but according to Cuvier the axis 

 and the third joint are soldered together. In the Cape whale 

 the whole seven are confluent into one piece. 



In the Eupliysetes Grayii the one bone, which is formed of the 

 seven cervical vertebrae, has the atlas and axis marked out in it 

 by their superior blunt conical transverse apophyses, as in the 

 Cape whale ; their inferior apophyses being evanescent as in 

 dolphins. The third and fourth vertebrae are thick, each marked 

 by a short conical superior transverse apophyse, and having a 

 separation, from each other and from the axis, distinguished by 



