360 Journal of Comparative Neurology. 



therefore, almost certainly sympathetic. This root, like 

 the preceding, runs dorsad in the meninges and then 

 breaks up into several minute twigs. The largest of 

 these runs back and within the cranium joins the most 

 cephalic branch of the second root. Of the other twigs 

 some appear to supply the meninges, but most, and these 

 containing the coarser fibres, rise to the cranial roof, 

 which they perforate, each by a minute foramen in the 

 frontal bone. Five such branches were followed and of 

 these three could be traced to naked sense organs on the 

 dorsal surface of the head. Probably the others have 

 similar destinations. 



On the opposite side of the specimen plotted the details 

 of the facial roots of the r. lateralis accessorius are some- 

 what different. The first root arises by several strands 

 essentially as figured for the left side, though the details 

 of their arrangement are not exactly the same. The 

 second root is wanting altogether, and as this is the case 

 on both sides of another specimen examined, I assume it 

 to be the more usual arrangement. The third root is 

 about as figured, though not exactly. As before, it con- 

 sists of some very fine fibres and some a little coarser 

 with heavier myelination. The latter come from behind 

 and clearly from the communis, the former arise a little 

 farther cephalad and probably from the sympathetic and 

 are provided with the little ganglion. The third root 

 breaks up into numerous branches, some of which were 

 traced to sense organs, as on the other side. In the upper 

 part of the cranial cavity this root sends back a large 

 branch which joins the main r. lateralis accessorius from 

 the first root. 



As the large scales covering the top of the head make 

 it difficult to get perfect sections, several surface prepara- 

 tions of the skin of this region were made to control the 

 sections. There are undoubtedly some more organs in 

 the region overlying the optic lobes than the plots indi- 

 cate, but that number is not large and is probably not 



