GENERATION OF POLYCLAD TCKHEM.AKI A. 335 



e-i.ibli-h tin- [M)int. There i- thru every reason in believe that 

 the central ner\ou- a comprises, not the yanijia alone, but 



tin- u .niylia phi- the nerve roots for a certain greater or le>s 

 di-tan.e I nun their origin. Kveii when the ^anijia arc com- 

 plt-ii-l;. removed, tin- capacitie- of tlu- central nervou- -v-u-m for 

 in-raiioii and -timulation are not wholly lo-t , if sufficient 

 portion- of the ner\ e roots near the u.nulia remain. In Mich 

 CS the amount of n-. ii.-ration i- ^rcaier than \\lu-n the IHT\ e 

 root- are al-o remo\ed. .iinl Croups of eye -pm^ ma\ appear. 

 In !a< t. in one < as I ob-erved th- eratioii of a ^mall luit 



di-iiiH . lionic nia-- .ifter the apparently complete remov.il 



of ili. ganglia. h seems not improbable that if our techni(|in- 

 ueie -iitth ienilv nermit removal of the ;.;.in;.;lia \\ithoiit 



iujinv io the iiei\i |it at their origin, the ri'-eiierat ion 



even oi i ; them-el\ well as of other parts, might 



In- a lino- 1 . ,i quit <uii)ili -te a- v, hen the -.m^lia remain. 



I,. \ . Morgan's I if !'-' "I ihe regenerated anterior end of the 

 nervous system alti-r n ni"\al of tl. _ lia -ho\\ - mils tilirillar 



>l i in lure and -he states thai miK fibril la- are pre-ent in I he mass. 

 Hut \\hen \\e lec.ill the l.ii i- as to the h i -I ol"^ii a I -iriictnre of 

 the iiei\e ioot^ it -eem- extreiiieK improbable that iMiiiJion 

 i i II- art tot.ill\ ab-eiit I'mm -in h i e-i net ai ec 1 masses. In all 

 - of the kind, \\hich I ha\e ob-ei\ed. -oine ( cll- a> \\ell as 

 t he 1 1 bl ilia- h.t\ e alu a\ - been ple-eiit ill the knot of ti--lle formed 

 b\ the union o| tin- nei \ i 



The de\elopment ol -pot- iii many of the cases \\iihoiit 



^.in-lia de-i ribi-d b\ Nb'i-aii i- lindonbledK due to re-eiiei al i\ 'e 

 pio, iii the remainin. . lionic ner\e roots. In m\ o\\ n 



experimeiil^ I ha\e found that in all cases, \\hate\er the method 

 of operation, \\heie the ^an^lia phi- a -ulln ieiit jiortion ol the 

 nei\e roots are ivmo\ed the re-ein-raiioii i- al\\a\- -li^ht, e\ e 

 >|>oi- do not de\elop and the animal ne\er -ho\\ - aii\ recovery 

 from il- -hi^^i-h nnn>poii-i\ e eondiiion, ;. c., it behaxe- in all 

 respects like a he. idle animal. <>n the other hand, where the 

 roots are laixelx intact . i e-eiierat i<ui i- more rapid and pio< eeds 

 lai I her, eye Spots often appear and the re. o\ erv of motor acti\ ity 

 and a|)pan-nt >poiilaneit\ 1 rei [iieiit 1\ OCCUrs to a \'er\ marked 



extent. 



' hild, 'Studi* },eti . \'I . Fig i;. p. 526. 



