30 THE INVOL UNTAR Y NER VO US S YSTEM 



become removed to a greater or less extent from their original 

 position during the process of development.* 



The next step in the investigation was obviously to find 

 out the functions of these three outflows and so attempt to dis- 

 cover their meaning. It so happened, however, that my ana- 

 tomical investigations had led me direct to the consideration of 

 the segmentation of the vertebrate and the meaning of its central 

 nervous system, a matter of such absorbing interest to me that I 

 determined to continue to research on those lines ; accordingly I 

 asked Dr. (now Sir John) Rose Bradford to undertake the sys- 

 tematic investigation of the functions of the nerves in all the roots 

 which contribute to these three outflows. He was very pleased 

 to undertake the research and published as its first fruits the 

 distribution of the vascular nerves in the thoracico-lumbar out- 

 flow. 



A more extensive investigation of the functions of these roots 

 was subsequently carried out by Langley and Anderson. 



* In my opinion a sympathetic motor nerve cell has from the beginning always 

 been in continuity with its particular peripheral organ (see chap. xi). 



