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The ramus ophthalmicus trigemini, after separating from the 

 ramus ophthalmicus lateralis, continues directly forward along the 

 lateral surface of the nasal capsule, there lying almost directly upon 

 the dorsal surface of the palatine cartilage. It lies at first ventral 

 to the hind end of the m. nasalis, but toward the anterior end of the 

 nasal capsule, where the m. palato-ethmoidalis superficialis begins, the 

 nerve is forced out of this relation to the m. nasalis and acquires a 

 position along the mesial surface of the m. palato-ethmoidalis super- 

 ficialis. There it soon separates into two divisions, a dorsal and a 

 ventral erne, which are respectively the nerves designated by Müller, 

 in his figures, as 5 l " and S ,l,i . The dorsal branch is the smaller of 

 the two. It runs forward and slightly upward and soon reaches the 

 angle formed between the mesial surfaces of the m. palato-ethmoidalis 

 superficialis and m. nasalis. There it continues forward, lying at first 

 along the ventro-lateral and then along the lateral surface of the 

 nasal tube, and sending certain branches inward to the outer surface 

 of that tube, and others outward, through the m. nasalis, to sub- 

 cutaneous regions. In this part of its course it rises gradually to the 

 level of the middle point of the mesial surface of the m. nasalis, and 

 near the anterior end of that muscle either passes outward between 

 the two parts into which the muscle there separates, or perforates 

 the ventral edge of the dorsal portion of the muscle. Continuing 

 forward beyond the muscle it either perforates the m. ethmoideo-nasalis 

 or passes on to the external surface of that muscle, and, crossing it, 

 continues to the extreme anterior end of the snout. The nerve is 

 said by Müller to innervate the m. nasalis and m. ethmoideo-nasalis, 

 but I am fully convinced, from the sections alone, that the branches 

 sent to those muscles simply perforate them, and do not innervate 

 them. The muscles are, moreover, quite certainly innervated by 

 branches of the motor component of the ramus maxillaris trigemini, 

 as will be later described. 



To further control the innervation of these muscles I have had the 

 several branches of the trigeminus stimulated electrically, by Mr. Allen, 

 in several different specimens. In no single case, when the ramus 

 ophthalmicus was stimulated, was any response whatever obtained 

 from any muscle ; while all the muscles said by Müller to be innerv- 

 ated by it responded immediately to stimulation of the ramus 

 maxillaris. 



After giving off this upper nerve, the ventral and larger division 

 of the ophthalmicus trigemini continues forward along the dorsal 

 surface of the palatine, and soon comes to lie between the palatine 



