14.! MI-:i;l>TI<- YAKIATIUN. [PARTI. 



ml j.air leaves between the second and third vertebrae, and the 



third pair leaves bet \\i-.-n the third and fourtli vertebra?. The braehial 



M- i> formed by the whole of the second pair together with parts nf 



tin- tirst and third pairs. (The details of the arrangement are compli- 



1 and \ary L'l-eatly in different forms.) In PIJMI a different arrange- 

 ni'-nt exists. The most anterior pair of nerves leaves the spinal 



HUM by [ ft'orntinij the tirst vertebra, and the pair which leaxes 

 between tin- lirst and second vertebra 1 is therefore ordinally the se<-<>inl 

 pair- "f -pinal nerves in this form; the pair which leaves between the 



nd and third \.-it. -br:e is the third, and so on. The brachial plexus 

 is mad. up ' -r the wlmle of the second nerve, nearly the whole of the 

 third nerve and nf a branch of the first. 



It tht-ii it wen- to be supposed that the pair of nerves which leaves 

 tin- cc.liiiun between tin- first and second vertebrae in 1'ipa is homo- 

 wit h tin- pair of nerves which leaves in the same place in /.'"/"/. 

 A'-, it is rlcar that lirtween the skull and the 2nd vertebra of J'ijm, 

 then- is an extra pair nf nerves not found in Rana. The number of 

 v.-rtebi;.- in /'i/,<i is however less than in liana. For in the former 

 then- an- only M-M-M nf these, making with the united sacral vertebra 

 and urn-t\le eight pieces in all; but in Rana there are eight prae- 

 .-aeraU. nne sacral, and counting the urostyle, ten pieces in all. In 

 ' only nne spinal nerve, the 10th, leaves the urostyle, while in 

 l'i r i two pair>, the '.'th and loth. pass out through the terminal piece 

 "f the \ertebral enliiiiin. suggesting that the diminution in the 

 niiinlier nf \eitebr-e i - due to the absence of separation between the 

 ( .th vertebi-a and the ui-n>tyle. The whole number of spinal nerves 

 i* theret'nr.- the -aine in bnth Rana and Pipa, but in the latter the 

 Ut pair pei-fnrate tlie Ut vertebra in addition to the 1'nd pair 

 whi.-h ; ,t between the 1st and L'ncl vertebra. l'"i I;I;HIM;I:]; ', 



M., Jen, Zi.. 1874, nil. p. LSI and y,,t, PI. vn. tig. 37; also Jen. 

 Zl.. 1 >7."i. \ 11. I'l. \i\. figs. .". and ('.. 



It waa suggested by STASTNII - (A.7//-6. d. vergl. Anat., p. 130, Xote) 

 that pcrhaj^ the l>t \ertebia nf /'//' n-pi-esents two coalesced verte- 

 br:e, but in an anatniniral e\aminat imi nf two specimens of I'ijiit, 

 I i. ringer (/..-. IsTl.p. IMIJ, fmind ao confirmation of this suggestion. 

 and developmental evidence also went to sheu that no such fusion 



ira in the ontogeny at leasl . K.OLLIKER, A., !'-,-//. /,/,,/.<. -med. 



\V m-Jun-'j, 1 Mill, \. p. -_'."ii;. 



A Fttrbringer saj - there is no satisfactory \\ay of bringing this case 

 nf /'/// into accord \\ith the .-ondition seen in lui,,,i. In the Urodela 

 tliere is of coarse a >ul.occiital be 



p 



A Fttrbringer saj - t 



nf 



is of coarse a >ul.occipital nerve between the skull and the 1st 

 vertebra \\hi.-h i> ao1 present in /,'///,/. and some resemblance to Pipa 

 '- 'I'"- bed; ll1 " in ih.- Orodela the 1st spinal does not actually 



' ( '"' ' - 1 " 1 " -I/"'"/' 7 '- Jahrb., L880, vi. ].. -_".I7. The statement 



\>y M.II -Hi. niii.' thiit tin- 11. -r\, - of /'./../ <m.l H. 1,1,1 .-..nvspoiid oerve for n.-rve, 



'Mvf in tli- rertebrii-. if estal.li -uld be 



iiiilM.rtJint: l.:it fr.ini tli,- \v;mt ..f il. tail, ,1 .1,-ci iptimi it is n..t clc:n- \\hctlicr this 

 I at I iy actual ilis-.-ctiun. 



I'lu- i~ .|n.-ti..n.'.l l.y AI...I.I-HI. M,, //,/,. ./;,,//., xix. is'.cj, p. ;u.'. n,,t<> The 

 "" ' mtaina iniu-i, ini|.,,rtant mallei li.-ai-in- ,.,, th,. N ;l iiaii..u i.f tli. -'nerves 



Lmphibia. rel tiiat thi^ papn did nut aj-p.-ar in time to enable nie to 



in.-.'i|'.'laU- the I'a.'t- it c.nitaiiis. 



