204 Journal of Comparative Neurology and Psychology. 



on cats to determine whether the cervical sympathetic, if allowed an op- 

 portunity to become connected with the peripheral nerve cells in the 

 course of the chorda tympani, will in part change their function from 

 vaso-constrictor to vaso-dilator. The superior cervical ganglion was 

 excised and the central end of the cervical nerve was joined to the 

 peripheral end of the lingual, which contains the chorda tympani 

 fibers. After allowing time for union and regeneration of the nerves, 

 the cervical sympathetic was stimulated ; it caused prompt flushing of 

 the submaxillary glands, and the effect was repeatedly obtained. 



The experiment is interj^reted as showing (i) that vaso-constrictor 

 nerve fibers are capable of making connection with peripheral vaso- 

 dilator nerve cells and becoming vaso-dilator fibers, and (2) that 

 whether contraction or inhibition of the unstriated muscle of the arter- 

 ies occurs on nerve stimulation depends upon the mode of nerve end- 

 ing of the post-ganglion ic nerve fiber. The cervical sympathetic gave 

 a less scanty and more proh^nged secretion than normal, so that some 

 of its uei-ve fibers had become connected with the peripheral secretory 

 nerve cells of the chorda tympani. c. j. H. 



Carlson, A. J. The Rate of the Nervous Impulse in the Spinal Cord and in 

 the Vagus and the Hypolossal Nerves of the California Hagfish (Bdellos- 

 toma doinbeyi). Amer. [our. Physiol., Vol. 10, pp. 401-418, 1904. 



By the use of a graphic method the rate of nerve transmission 

 was determined. Electrical stimulation served to initiate the impulse. 

 In the spinal cord the impulse moves antero-posteriorly, with but 

 slight individual variations, at the rate of 4.50 m. per second. The 

 rate in the opposite direction is 2.50 m. per second, and it is more 

 variable as well as slower than the rate for transmission in the antero- 

 posterior direction. The vagus shows a rate of about 2.50 m., and the 

 mandibular of 4.50 m. 



The fibers of the cord as well as those of the peripheral nerves in 

 the hagfish are non-medullated. As the author remarks, this low form 

 of fish has slower transmission in the spinal cord than have certain of 

 the annelid worms in the ventral nerve cord. Furthermore, "the rate 

 in the peripheral motor nerves is the lowest recorded for any verte- 

 brates and even lower than that in the motor nerves of some of the 

 molluscs." 



This paper is of value because of its suggestions of possible ap- 

 plications of the reaction-time method in the study of the physiology 

 of the nervous system, as well as for the interesting facts which it pre- 

 sents. Attention is called to evidence in the results of the experi- 

 ments described "that the rapidity of the processes of conduction in 



