WILLARD: CRANIAL NERVES OF ANOLIS CAROLINENSIS. 87 
reduction of the posterior roots; if such a reduction occurred in these 
two species, they would be in correspondence with Anolis. Fischer 
demonstrated the ramus externus definitely in nine other species of liz- 
ards and in the crocodile. Bischoff (’32) and Vogt (’39) had described 
this ramus externus as supplying a small twig to the cervical muscle, 
but this could not be expected, and was not verified by Fischer. 
Fiirbringer (’76, p. 649) in his account of the innervation of the 
shoulder muscles of saurians refers to the part taken in their innerva- 
tion by the vago-accessorius as though it were a regular feature to be 
met with in all forms. The ramus externus is distributed, he says, 
to the ventral half of the capiti-cleido-episternalis (capiti-dorso- 
elavicularis), where it as a rule anastomoses with the cervical plexus 
of the anterior spinal nerves. 
More recently Osawa (’98, p. 616) has described in Hatteria a 
spinal accessory having the typical superficial origin, which extends 
eaudally as far as the third spinal nerve. This accessory joins X, 
_and distal to the ganglion there is given off a weak ramus internus 
and a strong ramus externus, the latter going to innervate the muscle 
capiti-dorso-clavicularis. Schauinsland’s (:03, Taf. VIII, fig. 70) 
| observation on the embryo of the same form practically coincides with 
; Osawa’s description. 
There appears to be some confusion in Watkinson’s (:06) account 
| of this nerve in Varanus. She says (p. 467) “the ramus externus vagi 
jimnervates the muscle sterno-cleido-hyoideus near its origin from the 
\skull. This muscle also receiving innervation from the third cervical 
jnerve, the end fibers forming an intricate sling with those of the ramus 
jexternus.” Reference to her Plate XII, figs. 10 and 11, shows that 
\the author means “mm. capiti-cleido-episternalis.”” Another ambiguity 
rests in the use of the term “m. cucullaris”’ (Plate XII, fig. VIII) for 
ithe most superficial neck muscle. This evidently corresponds to the 
(sphincter colli of Anolis and, like the latter, is innervated by VII. 
; Notwithstanding the great number of papers that have appeared 
pn the morphology of the nervus accessorius, the subject is far from 
settled, and, in view of the great range of variation in the anatomical 
‘elations of roots and peripheral nerves, the necessity of microscopical] 
inalysis is obvious. Lubosch’s (’98 and ’99) extensive review of the 
ibject in vertebrates from the standpoint of comparative anatomy 
-mly tends to emphasize the fragmentary nature of our knowledge 
egarding this region in amniotes. 
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