V. KuPFFER, Cranial Nerves of J'erfcbratcs. 3315 



glion, persists as an eye-muscle nerve (com p. Fig. 8). 

 Should this conjecture be established, this nerve would not 

 belong to the spinal but to the branchial system. 



If one can say that the foremost pair of dorsal and ventral 

 spinal nerves are situated within the vicinity of the first prin- 

 cipal ganglion of the trigeminus, in the same way one meets 

 a second pair of dorsal spinal ganglia, connected with its 

 sympathic ganglia, mesad from the second principal gan- 

 glion of the same region and in the same transverse plane 

 with the exit oi the N. mandibularis from the principal gan- 

 glion just mentioned. I can state nothing definite concerning 

 the terminal twigs belonging to this pair. 



The same difficulty in following out the spinal nerves 

 exists in the region of the facialis. The large principal gan- 

 glion and the labyrinth vesicle take up the space between the 

 epidermis and brain almost entirely, and push the remaining 

 elements apart. I have not been able to demonstrate a dorsal 

 spinal nerve in the whole course, in a 4 mm. larvs, but have, 

 indeed, a spinal ganglion, wedged in between the principal 

 ganglion of the facialis and the chorda, and also a long sym- 

 pathic ganglion, lying close to the aorta, which gives off 

 fibres to the branchial nerve of the facialis. This spinal 

 ganglion probably fuses later with the principal ganglion. 



The pointed fore end of the first myomere of the body 

 pushes up close to the hind end of the principal ganglion of 

 the facialis, and even inserts itself slightly under the gan- 

 glion. The lateral muscles of the head do not first proceed 

 from this, but from the second myomere, close behind the 

 first branchial nerve of the vagus. Here, over the fore end 

 of the second myomere, for the time being, the regular series 

 of the spinal ganglia and spinal nerves of the trunk also 

 begins. 



This first myomere of the 4 mm. Ammocoetes lies thus in 

 the region of the glosso-pharyngeus, with its fore end over 

 the second gill pouch. I have not found a ventral spinal 

 nerve connected with the myomere, but have found a dorsal 



