THE RAMUS OPHTHALMICUS PROFUNDUS. 209 



glion between the dorsal and ventral angles. This latter^ 

 nerve is in a very interesting condition, and it would ap- 

 pear from Allis' description to be in a state of degeneration 

 (p. 533) — "When this last nerve was found, it always ac- 

 companied the ciliary nerves as they ran forward and out- 

 ward between the external and superior recti. Beyond 

 that point it was always lost, appearing sometimes to fuse 

 with the ciliary nerves, and at others to disappear in the 

 general tissues." 



In Menidia the profundus is still further reduced and 

 more intimately fused with the trigeminus. The portio 

 ophthalmici profundi is lost and the r. ophthalmicus pro- 

 fundus fused for its entire length with the radix longa. 



The peculiar and constant relations of the ophthalmicus 

 to the sympathetic are not diificut of explanation. The 

 "head part " of the sympathetic has one or more ganglia 

 associated with the ganglia of all of the cranial nerves, 

 doubtless including the primitive profundus. Now, the 

 sympathetic ganglion lying under the primitive profundus 

 glanglion having become connected with the oculomotor 

 nerve (either secondarily or primarily, if the III nerve 

 should prove to be the motor nerve of the profundus seg- 

 ment, as some maintain), it was retained in this position 

 during the backward migration of the profundus gan- 

 glion toward the Gasserian, and now appears as the ciliary 

 ganglion. 



Allis remarks that the superficialis trigemini and the 

 profundus seem to vary in relative importance directly as 

 the number of terminal buds found on the top of the head 

 and snout. The primary composition of these nerves is, 

 it seems to me, undoubtedly general cutaneous rather 

 than special cutaneous for terminal buds. The number 

 of the latter fibres is certainly an important factor, never- 



