ZOOLOGY: H. JORDAN 159 



found to be insensitive to localized currents. This indicates that the 

 rheotropic end organs are cutaneous; of these only the tactile corpuscles 

 were found to be of significance. This is shown by the following 

 experiments. Under normal conditions stimulation of the lips by 

 a glass rod produces a very violent negative reaction, and so, too, does 

 a current of water of the sort just described. The lips of a normal fish 

 were anaesthetized by the application of a 0.1% solution of cocaine. As 

 a result the reaction (and assumably the sensitivity) to tactile stimulus 

 disappeared completely, and also the reaction to the water current. Not 

 only that, but also the parallelism between the effects of the two sorts 

 of stimuli at any instant, both during the gradual benumbing of the 

 lips by the reagent and during their progressive recovery from insen- 

 sitivity, seemed to be complete. These facts indicate that the end or- 

 gans of tactile sensitivity serve also as the essential and organs of rheo- 

 tropic sensitivity. Other sensory cells, while they may in some cases 

 be affected by currents, apparently play no necessary part "in the re- 

 action here described. 



1 Contributions from the Bermuda Biological Station for Research, No. 56. 

 2 Lyon, E. P., Amer. J. Physiol., Boston, 12, 1904, (149-161). 



3 Parker, G. H., Washington, D. C., Bull. U. S. Fish. Com. for 1902, 1903, (45-64). 



4 Parker, G. H., Amer. Nat., Boston, 37, 1903, (185-204). 



6 Schulze, F. E., Arch. mikr. Anal., Bonn, 6, 1870, (62-88), Taf. 4-6. 

 Tullberg, T., Vet.-Ak. Bih., Stockholm, 28, 1903, (No. 15, 25 pp.). 



7 Verworn, Allgemeine Physiologie, 2te Aufl., 1897, (xi + 606). 



