VEETEBEATE ANIMALS. 

 CHArTEi! xxn. 



GEA'EKAL CHAUACTEItS (JF THE VERTEBRATA, 



The ti\"f sub-kiiji^iluuis wliicli \ve have previously considered — viz. 

 the I'mt, ,:,„(, Co:l,iil,'iiit<i, E:-I,i ntHhu-nuitu, Annul fx,i , and Jfulluxni^ 

 wei'e griiupeil tiiyi'ther )>y Jjaniarek into iine great division Avhich 

 he termed the J nrcrtihrntit. The remaining sub-kingdom, tliat of 

 tin; \'ci-trli,\itii, is so well-marked and com]]act a division, and its 

 distinctive characters are su niimennis and s.. iniportvint, that this 

 mode of \'ie\\'ing lie,' animal kingdom is, at a]i\' late, a very conve- 

 nient one. 



The snli-kingdipui \'ir/,'hriil(i includes the \\w great classes of the 

 Fishes {/'ixrrs')^ Am|ihiliiaus, Iteptiles, liirds (.lrr»), and jNIammals ; 

 and the name of the suh-kingdom is ch'riveil from the very general, 

 though not univei'sal, i>resence of the liony a.\is known as the "verte- 

 bral column" or hacklioue. One of the most fuudaniental of the 

 distincti\'e chaive-teis of Yertehr.ate tniimals is to be fiauid in the 

 fai't that tin; ni.aui massi's of the neivous system (that is to say, the 

 brain and spinal cord i .are coni|iletely shut off from the general cavity 

 of the boily, hi all Inviutebr.ate animals ( (ig, loT, A) the body may 

 lie regai'd(;d as a single tube, enclosing tdl the viscei'a ; and con.se- 

 queiitly, when a distinct nci'\'ous system and alimenlai'V canal are 

 Jiresent, these are in no w.-iy shut olf fii.ui one anolher. The tr.a.ns- 

 verse si'ction, llo^^■e\-e|■, of any \'erb'bra,te animal (lig. loT, T>) shows 

 i/rit tulles, one of \\liieh <-oiif:iins llie gie.'it uervous .axis (//\ or brain 

 ;uid spin;d cord, A\'liilst the otliei' c(Hit;iins the alimentarv canal, the 

 (hief c'iiviil;ilory org;ins, and eert.iin jiorlions of the neiA'ous svstem 

 (ii) wliiili ;nv kn'i«ii lo aiiatjauists ;is the " sym|i:ithetic " svsti'm. 



