THE MUSCLES 49 



skeleton and its related muscles in Urodeles, Anura, and Reptiles, 

 but it was Wilder (1892 and 1896) who first gave an exact descrip- 

 tion of the larynx and its muscles. He endeavoured to homologize 

 the latter with those of the visceral arches. A brief resume of his 

 hypothesis and of those of subsequent workers in this field is given 

 on p. 272. Further contributions to the discussion of the homologies 

 of the laryngeal muscles were made by Goppert in 1894 and 1898. 

 In 1902 Burkard undertook a comparative study of the muscles 

 surrounding the orbit in the various classes of vertebrates, and 

 included a description of the M. levator bulbi of Salamandra. A 

 very detailed and exact description of the muscles supplied by the 

 Vllth, IXth, Xth, and hypoglossal nerves in Salamandra and Triton 

 was published by Driiner in 1901. He also describes the nerves 

 themselves and the hyobranchial skeleton. Two years later (1903), 

 and again in 1904, Driiner supplemented this account by describing 

 the same region in other Urodeles, and included some theoretical 

 considerations on the homology of the chorda tympani, and of the 

 larynx. His whole work is a classic and very accurate. A compara- 

 tive study of the jaw-muscles of vertebrates was published by 

 Lubosch in 1913 and 19 14, and while he does not deal with 

 Salamandra itself, his work is important from a comparative point 

 of view. In 19 14 Luther described the muscles supplied by the 

 Vth nerve, which include the M. levator mandibulae and the M. 

 levator bulbi. He deals with Salamandra. Lastly Edgeworth (1920 

 et seq.) has published many papers dealing with the development 

 and homologies of the muscles of the head in Amphibia and other 

 vertebrates, and was the first to show that the larynx and its muscles 

 have no phylogenetic relationship with the visceral arches. It is 

 Edgeworth's nomenclature which has been adopted here. 



2. Muscles of the Eye (PI. XIII, fig. 57). 



These are eight in number, namely, four recti, two oblique, 

 together with the MM. levator and retractor bulbi. Of these, 

 seven are described below, while the eighth — the M. levator 

 bulbi — belongs to the muscles of the Vth nerve and is described on 

 P-55- 

 M. rectus superior (m.r.s.). 



This muscle arises from the dorso-posterior angle of the orbit and 

 runs antero-laterally, broadening somewhat at its insertion on the 

 dorsal section of the ambitus of the bulbus oculi. Its origin is 

 tendinous. 



4038 Tj 



