ORFGIN AND STRUCTURE OF THE HEAD • 115 



nium in which the occipital region represents a muUiplum 

 of vertebrae, not one vertebra as is rendered probable by 

 ontogeny, by the absence of occipital nerves and by 

 the fact that the anterior spinal nerves innervate the 

 hypobranchial musculature. FuRBRlNGER himself, as we 

 have seen (cf. p. 100), recognizes that no facts can be adduced 

 in favour of this supposition. He only mentions (1. c. p. 486) 

 that once, in a young Megalobatrachus, he believes he has 

 found an extremely fine nerve-thread in the occipital region. 

 He considers it as a last remnant of more such nerves and 

 calls it z but does not feel quite sure of his observation 

 which, however, has been afterwards confirmed for embryo- 

 nal stages of different Amphibia. OSAWA (1902) found it in 



Ttabecufa ^-r^-^-'^jr^r ""^^^ 



Cornu trabec. 



ForN.ocuhm 

 B^oc. ascendi 



¥ 



fara articul. 



Fig. 21. Rudiment of the skull of 5/redo/ip/sa/orm/s. Arc.occ. occipital 

 arch, Caps, audit, auditory capsule, after Stohr, 1879. 



Megalobatrachus, DRuNER (1901, 1904) in larvae of Triton 

 and Salamandra, PETER (1898, p. 42) and MARCUS (1910, 

 p. 376) in Gymnophiones and GOODRICH {\^\\)'m Siredon. 

 At the end of this chapter we shall revert to this nerve and 

 show that it evidently represents the ventral root of the spinal 

 nerve of which the ganglion has fused with that of the primary 

 vagus (the "spinalartiger Vagusanhang" of Hatschek, 

 1892) and corresponds to FuRBRlNGER's occipital nerve x 

 in Selachians like Scy Ilium. 



k 



