i HI: . 450 



of the trii/eminu^ and. as i 

 motoriu>. The second M^iiiei! 1 '..<>{ ly t 



of tin- I riueii.iuu^ and t IP 



origin. The dorsul roots of the thinl (and segments are 



repiv>ellted 1V tilt- : 



Tin- tit'tli -e.me-it ix>aBee8e8 only the exclusively sensory 

 \\lii.-ii arises from the neural ridge. The segments 



from the sixth to the nintli inclusive are innervated by the vagus and 

 tin- hypo:l.i-vNus. the former of which i> 



. tli.- latter a series of ventral ones. 



\ _ \\ : : - aivount. not wit l^tan.liii^ l h> p-iK-ral agree- 



ment, t here st ill eX 



I'ftli'- << I'ltalic to-tjinfiitx <ttt<t t/mt of the trunL \ nthe 



lical (lie ventral, motor rooN (o( nlomotorius, trochlearis, alxlucens, 

 liypn^lossus) supply only a part of the mu-rulat tire the eye- 

 inusclcs ami crrtain mu>rlrs that run from the skull to the pe<" 

 ; that is to >ay. mu>rlr> \\hirli. U lias already been stated, 

 ped out of the cephalic se^menN. Other p-oup> of muscles, 

 which arise from the lateral pi bfl head, are i' 



the tri^emiiuis ami fucialis, which have a d-T | the 



doi>al rootfl of the nerves in the head would be distinguished from 

 those in the trunk by the impor tain mot 



well as seii-ory liluv-. I5i:i.i/s law w.cild c;>a>ejuent ly possess a 

 limited application for the head region of Vertebrates, and would 

 have to 1>L replaced l.y the following: law. tormula'ed l,y \Vi.ini: : 



"The dorsul rootfl ot the head-nerves are not e.\Hu>i\el\ 

 l.ut also innervate the musclefl ' tV-.m the lateral plate^. 



however, thosci from the primit; 



" The ventral roots are motor, but innervate only the muscle 

 the primitive BegDMI , n't tho^- of the lateral plates." 



In view of this fundamental dilt'e; ence. I desire to express a douht 



whether there are not after all enclosed in the facial^ and triL-en: 



parts which are established as ventral roots, but have hitherto been 

 overlooked, as in the beginning all the ventral roots in the 1: 

 (see BALFOUR) were overlook- <1. 



According to RABL the nerves <> l>art of the head only- 



>pharyngcus, vagus, accessorius, and hypoglossus can be compared with 

 the type of spinal nt : - of the anterior part of the head, on the 



contrary, the olfactorius. optinis, trL'i'ininus. ti^rthrr with thox- . 

 muscles and the acu- .is, belong in a separate category, just as tho 



four most anterior head-se;-:: 



