384 SYMPATHETIC NERVOUS SYSTEM. 



BIBLIOGRAPHY OF THE PERIPHERAL NERVOUS SYSTEM. 



(351) F. M. Balfour. "On the development of the spinal nerves in Elasmobraneh 

 Fishes.'' Philosophical Transactions, VoL CLXVI. 1876; vide also, A monograph on Ilie 

 development of Elasmobranch Fishes. London, 1878, pp. 191 '216. 



(35 2 ) W. His. "Ueb. d. Anfange d. peripherischen Nervensystems. " Archiv f. 

 Ana't. u. Physio'., 1879. 



(353) A. M. Marshall. "On the early stages of development of the nerves in 

 Birds.'"' Journal of Anat. and Pln/s., Vol. xi. 1877. 



(354) A. M. Marshall. "The development of the cranial nerves in the Chick." 

 Quart. J. of Micr. Science, Vol. xvm. 1878. 



(355) A. M. Marshall. "The morphology of the vertebrate olfactory organ." 

 Quart. J. of Micr. Science, Vol. xix. 1879. 



(356) A. M. Marshall. "On the head-cavities and associated nerves in Elasmo- 

 branchs." Quart. J. of Micr. Science, Vol. xxi. 1881. 



(357) C. Schwalbe. "Das Ganglion oculomotorii." Jenaische Zeitxchrift, Vol. 

 xni. 1879. 



Sympathetic nervous system. 



The discovery that the spinal and cranial nerves together with 

 their ganglia were formed from the epiblast was shortly afterwards' 

 extended to the sympathetic nervous system, which has now been 

 shewn to arise in connection with the spinal and cranial nerves. The 

 earliest observations on this subject were those contained in my 

 Monograph on Elasmobranch Fishes (p. 173), while Schenk and 

 Birdsell (No. 361) have since arrived at the same result for Aves 

 and Mammalia. 



In my account of the development of these ganglia, it is stated that 

 they were first met with as small masses situated at the ends of 

 short branches of the spinal nerves (fig. 275 sy.g}. More recent inves- 

 tigations have shewn me that the sympathetic ganglia are at first 

 simply swellings on the main branches of the spinal nerves some w r ay 



below the ganglia. Their situation may be 

 understood from fig. 274 sy.g, which belongs 

 however to a somewhat later stage. Subse- 

 quently the sympathetic ganglia become re- 

 moved from the main stem of their respective 

 nerves, remaining however connected with 

 those stems by a short branch (fig. 275 sy.g}. 

 I have been unable to find a longitudinal 

 commissure connecting them in their early 

 stages ; and I presume that they are at first 



independent, and become subsequently united 

 FIG. 274. LONGITUDINAL . . , 1-1 



VERTICAL SECTION THROUGH In to a continuous cord on each side. 

 PART OF THE BODY WALL OF The observations of Schenk and Birdsell 



AN ELASMOBRANCH EMBRYO on the Mammalia seem to indicate that the 



SHEWING PART OF TWO SPINAL . . . 



AND THE SYMPATHETIC mam parts ol the sympathetic system arise 



GANGLIA BELONGING TO THEM, in continuity with the posterior spinal gan- 



ar. anterior root; pr.pos- gjia: they al so shew that in the neck and 



S^'iKSTSSS other P arts the sympathetic cords arise as a 



cle-plate. continuous ganglionic chain. The observa- 



