142 STRONG. [Vol. X. 



In Ecker's Anatomy of the Frog, p. 183, it is said that "Hoff- 

 mann describes a communicating branch of the Hypoglossus 

 to the * pneumogastric nerve/ which the translator has not 

 been able to discover and which no other observer has men- 

 tioned." It is quite probable that this is the corresponding 

 branch in the tadpole, thus partly verifying Hoffmann's obser- 

 vation. In a tadpole examined in which the metamorphosis 

 had begun this branch did not unite with the Hypoglossus. It 

 appeared here to innervate possibly the M. interbranchialis also. 

 Whether it was concerned with the innervation of any of the 

 Mm. marginales could not be certainly determined. Branches 

 J, ^, 5, 6, and 7 are given off practically together, and from 

 them some coarse fibres separate, forming the R. accessorius to 

 a capito-scapular muscle probably representing the M. cucul- 

 laris (::= 4a}). 



At the point of separation at 929 of the branch just 

 described, the trunk of the IX + X consists of two portions. 

 The outer of these is mainly fine-fibred, but with some 

 coarse fibres also. It is still ganglionated, the ganglion cells 

 belonging apparently to the fine fibres. The inner portion is 

 described below. The outer ganglionated portion now bends 

 ventrad, separating from the inner, and divides (910) (6 and 7). 

 It here also loses its ganglion cells. The ventral of the two 

 divisions (6) gives off two or three fine-fibred twigs, which 

 supply the epithelium of the outer angle of the pharynx in this 

 region and some distance cephalad. One of these twigs [6 b) 

 proceeds cephalad and at 759 gives off a twig which contains a 

 few ganglion cells and supplies the mucous membrane of the 

 pharynx ventral to it. At 757 the nerve contains a clump of 

 ganglion cells, and here divides. The inner part {6 b^ passes 

 mesad to the mucous membrane of the roof of the pharynx. 

 The outer part (p b^ supplies the membrane of the roof of the 

 gill cavity, which opens into the pharynx here. The remainder 

 proceeds caudad to 919, around one of the Mm. levatores, and 

 bends cephalad under the latter, giving off a small twig {6 c) 

 proceeding ectad, which could not be traced further. This twig 

 takes from the nerve the few coarse fibres it contained. There 

 is reason to believe (see p. 143) that this twig has finally a cutane- 



