RAMUS MANDIBULARIS VII. 153 



It turns toward the median line, enters the m. genio- 

 hyoideus and then turns caudad in the substance of the 

 muscle {m.ghy.)^ which it supplies for almost its entire 

 length. Within the muscle it anastomoses with its fellow 

 of the opposite side. Some fibres also emerge upon the 

 surface under the skin of the copula and are, I think, un- 

 questionably of general cutaneous nature. 



Within the m. genio-hyoideus a twig of very coarse 

 fibres passes to the extreme ventral surface, then cephalad 

 near the median line {m. im.). Having reached the level 

 of the m. intermandibularis, it goes dorsad and enters the 

 middle of that muscle spreading out among its fibres in 

 the manner typical for motor nerves. On the opposite 

 side of this specimen this twig pursues a similar course 

 except for the fact that it separates from the motor fibres 

 destined for the m. genio-hyoideus before they have 

 entered that muscle. They then run inward along the 

 dorsal instead of the ventral surface of the genio-hyoideus 

 and enter the m. intermandibularis at about the same 

 place as those of the other side. 



The relations of this anastomosis from the trigeminus 

 for the mm. genio-hyoideus and intermandibularis and the 

 adjacent skin were traced on the opposite side of this 

 specimen and on both sides of several others and in all 

 cases they were as above described. Osmic acid prepara- 

 tions (mounted unstained after fixation in Hermann's 

 fluid) show with especial distinctness that this nerve arises 

 from the trigeminus and not from the facialis. 



The remaining fibres of this communicating branch 

 from the trigeminus after the separation of the branch 

 last described, join the r. mandibularis externus VII and 

 from the facialis portion of the mixed trunk thus formed, 

 there arises at once a small twig {jn. VII. 12) for the third 



