willard: cranial nerves of anolis carolinensis. 49 



of the prootic bone, being bounded anteriorly by the membranous 

 part of the cranial wall (Plate 1, fig. 2; for. V). 



Before the ganglion is reached, the root shows a distinct separation 

 into three parts, which in cross section appear as three unequal seg- 

 ments of a circle. The largest is the dorsal segment, which passes 

 into the main part {gn. V) of the ganglion (semilunar of Fischer); 

 the ventral comprises the motor neurons, while the median division 

 from this point on is free from all other connections and passes into 

 the ophthalmic ganglion (Plate 2, fig. 4; Plate 3, figs. 6, 7, gn. V; gn. 

 opth.). 



The motor components, thus segregated just proximal to the gan- 

 glion, are almost exclusively distributed in small pure rami directly 

 from the ganglion (Plate 3, fig. 6). A few motor fibers are, however, 

 included in mandibular V and reappear in several small mixed rami 

 innervating a part of m. mylo-hyoideus (Plates 2 and 3, figs. 5 and 6). 



Those rami which supply the dorsal and lateral jaw musculature 

 arise from the dorsal division of the main motor bundle. This passes 

 across the ventral side of the ganglion and the base of mandibular V 

 to be split into two rami, one of which (cap. md. 1 and 2) supplies 

 chiefly the m. capiti mandibularis, and the other (pt.) the greater 

 part of the m. pter,ygoideus. Of the former a part passes directly 

 dorsad, while the rest follows the course of maxillaris V as several 

 slender rami to supply the anterior part of these muscles (Plates 2 

 and 3, figs. 4 and 6). 



The motor components which do not enter into this dorsal and 

 lateral distribution pass directly cephalad on the ventral face of the 

 ganglion. A part follows for a short distance mandibular V on its 

 ventral side and then divides, one branch (pt-m.d.) going to innervate 

 the m. pterygo-mandibularis, the other (pt.) to innervate the deeper 

 part of the m. pterygoideus. The rest separates into three rami, two 

 of which are very small. Of these one (pt-par.) innervates m. pterygo- 

 parietalis, the other (pt-sph. p.) m. pterygo-sphenoidalis posterior. 

 The third ramus (protru. oc.) is larger than either of these two. It 

 passes cephalad to the orbit to innervate m. protrusor oculi and m. 

 depressor palpebrae inferioris. Because of its special functional and 

 structural relations, this nerve demands a more detailed account. 



Ramus ad m. depressor palpebrae inferioris (dep. palh. if.). This 

 ramus is recognizable on the ventral side of the main motor bundle 

 opposite the proximal end of the ganglion (Plate 6, fig. 17). The 

 bundle as a whole has a characteristic appearance, the fibers being 

 well medullated but somewhat finer than those of the other motor 



