56 



Scientific Proceedings (88). 



cervical nerves have been included in the section than if the 

 thoracic nerves alone are affected. 



3- The results of combined section of the dorsal roots of the 

 spinal nerves and the vagi are similar to the effects of combined 

 section of the brain stem below the corpora quadrigemina and the 

 vagi. Transection below the corpora quadrigemina adds little or 

 not at all to the severity of the effects following section of the 

 dorsal roots. 



4. Costal respiratory movements are resumed after section of 

 dorsal roots, brain stem below the corpora quadrigemina and 

 phrenics if the vagi are intact. 



We believe that these experiments bring the intercostal 

 muscles into line with the other skeletal muscles so far as the 

 functional relations of afferent to efferent spinal nerve roots are 

 concerned. 1 



We believe also that the experiments show that it is necessary 

 that afferent impulses shall not merely have access to the central 

 system, but that they shall go to a particular part of the central 

 system in order to fulfill their function. In the case of the 

 respiratory movements, afferent impulses from the intercostal 

 muscles must go as far up as the corpora quadrigemina. The 

 medulla oblongata seems sufficient for the establishment of any 

 necessary connection of the vagi with efferent paths to the 

 respiratory muscles. 



142 (1320) 



A case of hereditary ataxia (?) in pigeons. 



By Oscar Riddle. 



[From the Carnegie Station for Experimental Evolution, Cold Spring 

 Harbor, L. I., N. Y.\ 



From an egg produced under the weakening influences of 

 "reproductive overwork " a female pigeon was hatched (in 1914) 

 which showed a marked lack of power over the voluntary move- 

 ments of the head and body. Thi s lack of coordination was 



'Sherrington, Schafer's "Text Book of Physiology," London, 1900, vol ii 

 P- 797- 



