THE VERTEBRA IN FISHES. 48 



These, beiug usually developed from distinct and independent 

 centres, I have termed "autogenous" elements (xix. p. 518.), Other 

 parts, more properly called processes, which shoot out as continu- 

 ations from some of the preceding elements, are termed " exogenous :" 

 e. fj. (t) the diapophyses, or upper " transverse processes," * and (z) 

 the zygapophyses, or the " oblique " or " articular processes " f of 

 human anatomy. 



The autogenous processes generally circumscribe holes about the 

 centrum, which, in the chain of vertebrte, form canals. The 

 most constant and extensive canal is that (Jiff. 8. n) '\. formed 

 above the centrum, for the lodgment of the trunk of the ner- 

 vous system (neural axis) by the parts thence termed " neurapo- 

 physes." The second canal {Jiff. 8. h)^^, below the centrum, is in its 

 entire extent more irregular and interrupted ; it lodges the central 

 organ and large trunks of the vascular system (htemal axis), and is 

 usually formed by the laminae, thence termed " htcmapophyses." At 

 the sides of the centrum, most commonly in the cervical region, a 

 canal (Jig. 9. v) is circumscribed by the pleurapophysis or costal 

 process (ih. pi), and by the diapophysis or upper transverse process 

 (ib. t), which canal includes a vessel, and often also a nerve. 



Thus a typical or perfect vertebra, with all its elements, presents 

 four canals or perforations about a common centre ; such a vertebra 

 we find in the thorax of man, and most of the higher classes of Ver- 

 tebrata {^g. 6.), also in the neck of many birds. In the example 

 from the latter class (^g. 9.), the htemapophyses (A, s) are anchy- 



trunsversi vertebra: ; Querforsatz, Carus ; Untere Querforsatz, Germ. ; Ajmphi/se trans- 

 verse, Cuv. ; Paraal, Geof. ; Para-vertebral elements. Grant. 



§ Gr. jjlewa, a rib ; and apnplit/.sis. Syn. Pi-ocessiis Iransversus vertebra; cervicalis, 

 Costa sev, pars vertebralis, sett ossea, casta;. Ruckentheil and Ohcr-sternal-theil des 

 Urwirbelbogens, Carus ; C6tes vertebralcs, Cuv. ; Paraal, Geof. ; Cata-vertebral ele- 

 ments. Grant. 



II By Syncope for liaBtnatoapophyses, from Gr. haima, blood ; and apophysis. 

 Syn. Cartilago costce, seu pars sternalis eostce : in the abdomen, inscriptiones tendinew 

 musculi recti ; Unter- sternal theil des Urwirbelbogens, Carus ; Bogenstiicke des Bauch- 

 wirbel, Carus ; Untere Wirbelbogen, Ger. ; Cutes sternales, Cuv. ; Os ploij6 eti chevron, 

 Cuv. ; Cataul, Geof. ; Cata-vertebral elements. Grant. 



If Syn. Processus spinosus vertebra:. Its base is the Oberer Tertiar-ivirbcl, Cams ; 

 its apex is the Oberer Dorn-forsatz, Carus ; Apophyse epineuse, Cuv. ; Epial, Geof. ; 

 Epi-vertebral elements. Grant 



** Syn. Ossa steriii et pi-ocessus ensiformis ; in the abdomen, "linea alba." Sternal- 

 wlrbel KlJrper, Carus ; Unterer Dorn-forsatz, Carus. 



* Diapophysis, from Gr. dia, trans, across; and apophysis. Syn. Radi.v posticus 

 processus transversi I'ertcbra; and processus transversus. Qucforsatz, Carus ; Obere 

 Querforsatz, Germ. ; Apophyse transverse, Cuv. 



t Zygapophysis, from Gr. zugos, junction ; and apophysis. Syn. Processus obliquns 

 vertehrcB ; Seitlicher Tertiar-wirbcl, Carus; Gelenk-forsatz, Germ.; Apophyse articu- 

 laire, Cuvicr. 



\ Ruckenmarks-kanal, Carus. \^ Aortcnhanal, C^irus. 



