WORK UPON VISCERAL AND ALLIED NERVES. 43 



fibres running into the nervi erigentes, but never found 

 them (rabbits). They always passed through the second 

 and third anterior roots. 



To the lungs. — Bradford and Dean ^ describe vaso- 

 constrictor fibres to the pulmonary vessels as occurring 

 in the anterior roots of the third, fourth and fifth thoracic 

 nerves and to a less extent in the sixth and seventh. 

 They experimented upon dogs, taking simultaneous tracings 

 of the variations of pressure in the pulmonary artery and 

 carotid. Their results have been confirmed by Francois 

 Franck.' He criticised their method as not being the best, 

 and liable to introduce factors difficult to interpret. He 

 therefore took simultaneous pressure tracings of the pul- 

 monary artery and left auricle, and required as a test for 

 constriction of the pulmonary artery a simultaneous rise of 

 pressure in the artery, with a fall in the auricular pressure. 

 In this way he finds that the constrictors are chiefly placed 

 in the second and third thoracic nerves, and that none are 

 found below the fifth and sixth. 



With regard to the origin and distribution of the vascular 

 nerves to other oreans, it will be more convenient to state 

 what is known of them when discussing the general nerve 

 supply of each organ. In this way we shall save repetition, 

 for the origin of the vascular nerves is the same, as a rule, 

 as that of the visceral fibres. 



THE CARDIAC NERVES. 

 The accelerator nerves, as Langley ^ has shown, leave the 

 cord chiefly by the second and third thoracic roots, to a less 

 extent in the fourth thoracic, and to a much slighter extent in 

 the first and fifth thoracic. It is indicated by a few experi- 

 ments, though not conclusively proved, that the cells on the 

 course of these fibres lie in the ganglion stellatum and inferior 

 cervical ganglion. The experiments were carried out on 

 cats. The spinal origin of these fibres is confirmed for the 

 dog by^Bayliss and Starling.* 



^Journ.of FhysioL, vol. xvi., p. 34, 1894. 



2 Arch, de Physiol, vol. xxvii., pp. 744 and 816, 1895. 



^ Phil. Trans., vol. clxxxiii., p. 85, 1892. 



^Journ. Physiol, vol. xvii., p. 126, 1894. 



