ELEMEN7'AR Y ANA TO MY. 



[LESS. 



into it of a neighbouring ossification (when it is said to be 

 exogenous '), or by an independent centre (when it is said to be 

 autogenous 2 ), constitutes but a very secondary and unim- 



FIG. 73 ANTERIOR SURFACE OF VHRTEBR^E OF DOLPHIN {Globiocepkalu* 

 melas). 



A, fifth thoracic ; B, seventh thoracic ; c, eighth thoracic ; r>, first lumbar ; r, rib ; 

 m, metapophysis ; t, transverse process. The dotted lines indicate the posi- 

 tion of the neuro-central suture. 



{Prom Prof. Flowers "Osteology") 



portant distinction ; since neural arches (as in the tail of 

 the Dog) or neural spines (as in trunk vertebrae of some 

 Ungulates) may ossify in either mode. 



In the same way, transverse processes, both capitular and 

 tubercular, may be formed by outgrowths of the central ossi- 

 fication only, or by extensions ot the lateral ossification, or 

 by the concurrence of both these parts, as in Plesiosauria and 

 some Cetacea (see Fig. 73). 



The presence of epiphyses on each side of the body and at 

 the tips of the neural spines, transverse processes, and meta- 



1 From efo>, outside, and 



2 From uvi6(;, self, and ye 



t, to arise. 



