willard: cranial nerves of anolis carolinensis. 95 



2. Second spinal nerve. The ventral root of the second spinal, 

 which constitutes the entire nerve, is similar to that of the 3rd spinal, 

 being composed of coarse somatic-motor fibers arising from several 

 bundles that have their origin in the ventral-horn cells. The 2nd spinal 

 is somewhat smaller than the 1st. The rootlets in each case combine 

 to form a compact bundle, which passes out through the intervertebral 

 foramen and immediately divides into a large dorsal ramus (Plates 2, 

 3, spi.d.2) and a smaller ventral ramus {spi.v.2). A lateral ramus 

 {spi. 1.2) is given off as a branch of the dorsal ramus. 



The ventral ramus passes ventrad between the neck muscles, where 

 it turns abruptly caudad to cross the ventral ramus of the 3rd spinal 

 on its median side, giving up a portion of its fibers to that nerve, as 

 already mentioned. The rest continues caudad to be distributed to 

 the ventral neck muscles in the region of the 4th spinal nerve. 



The dorsal ramus of the 2nd spinal is a large branch, which supplies 

 the dorsal and lateral neck musculature. 



3. First spinal nerve. This nerve (Plate 7, fig. 23) has the largest 

 number of somatic motor fibers of any yet described. It supplies the 

 dorsal muscles with a large dorsal ramus, as does the 2nd spinal, and, 

 in addition, sends a good sized branch to the ventral side to innervate 

 the omo-hyoideus and sterno-hyoideus muscles. The large root 

 trunk passes out between the cranium and the first vertebra. Just 

 outside the foramen it divides into ventral and dorsal rami. 



The ventral ramus (Plates 2, 3, figs. 4, 6, spi. v.l) passes ventrally 

 along the body of the vertebra and gives off one branch supplying the 

 ventral cervical musculature, and another that passes between the 

 longus colli and more superficial muscles. The latter then turns 

 slightly dorsad to pass on the dorsal side of X and the sympathetic 

 nerve, attaining a position alongside the third root of XII, with which 

 it is sometimes loosely bound. From here it passes ventrally (Plates 2, 

 3, figs. 5, 6, omo-hy. and stn-hy.) between the omo-hyoideus and 

 sterno-hyoideus muscles, both of which it richly supplies. 



The dorsal ramus {spi. d.l). This splits into three branches (Plate 3, 

 fig. 6), the lateral (Plate 7, fig. 23, spi. l.l) is distributed immediately 

 to the adjacent muscle, another to the ventral part of the longissimus 

 muscle, and the largest to the dorsal neck muscle, a portion being dis- 

 tributed at once to the muscle lying alongside the vertebra (Plate 7, 

 fig. 23), while the rest passes into the most dorsal division of the 

 longissimus, where it divides into four small terminal branches, two 

 passing cephalad and two caudad. 



4. Connections of first three spinal nerves with sympathetic. While 



