in Anatomy and Physiology. 259 
of fishes. It is a branch from the nervus lateralis and appears to 
have been hitherto unnoticed. Prof. Wyman remarks: 
“ The observation of the existence of a dorsal nerve gives ad- 
. ditional importance to the discovery of the nervus lateralis by 
Van Deen; and if to these we add those branches of the vagus 
described above, which pass along’ the branchial arches, the anal- 
f the larve of Batrachians to fishes becomes much more 
striking than there has been reason hitherto to regard it.”—p. 37. 
ction V. treats of the philosophical anatomy of the cranial 
nerves and skull. Prof. Wyman gives his preference to the three 
vertebree theory of the constitution of the cranium. ays: 
“If we apply the analogies of the spinal chord and vertebral 
column to the cranium and its nerves, we ought to base our de- 
terminations on the repetitions of true spinal nerves and of the 
true vertebral elements. If the theory be true which redtfces 
the cranial nerves (exclusive of the special sense nerves) to three, 
namely, the trigeminus, vagus, and hypoglossus, then we ought, 
4 priori, to detect at least three vertebral segments. This con- 
clusion agrees perfectly well with the determiuation from osteol- 
ogy. . . . . . . These vertebre may he designated as 
follows: 1st, the occipital, of which the basilar bone is the body ; 
2nd, the parietal, of which the posterior sphenoid is the body ; 3d, 
the frontal, of which the anterior sphenoid is the body.”—p. 41. 
In concluding this section, Prof. Wyman has some very notice- 
able remarks on the interpretation to be given to the jaws and 
other bones of the face in connection with the three vertebrae 
theory. After alluding to the fact that the latter are strictly ap- 
pendages of the mucous membrane, and that the jaws and other 
tooth-bearing bones, as well also as the hyoid bone, are developed 
in intimate relation with the alimentary canal, and that primarily 
the mouth and nostrils are but a single cavity, he remarks: “ We 
have strong grounds for the hypothesis, that all the bones of the 
face which are developed in the walls of the primitive cavity of 
the mouth which they surround, are in their anatomical and phys- 
iological relations splanchnic, connected either with digestion or 
respiration, rather than parts of the endo-skeleton of animal life.” 
42 
—p. 42. 
The last two sections (VI and VII) treat respectively of the 
spinal nerves and of the sympathetic nerve. iey are full of 
details most interesting to the thorough anatomist ; but our space 
will ndt allow us to refer to them specially. It should be men- 
tioned, however, that Prof. Wyman has distinctly made out 
a coccygeal nerve, thus making the number of pairs of spinal 
nerves ten instead of nine, the number usually enumerated ; an 
