G. GENERAL NATURAL HISTORY AND ZOOLOGY. 355 



in a manuscript recently printed in France, where in Gouber- 

 ville's diary, under date of December 27, 1555, he speaks of 

 having had brought to him an Indian cock and hen. Proba- 

 bly the bird must have been known for some time, from this 

 casual mention, as the same journal contains notices in detail 

 of new forms of animal and vegetable life which had attract- 

 ed his attention. 10 B, June 3, 60. 



STONE ARROW IN A HUMAN" TIBIA. 



Baudrimont gives an account of a human tibia found in 

 Aveyron which had a stone arrow-head inserted in it, and 

 which had remained adherent, and had caused a considerable 

 exostosis of the bone. But what is most remarkable is the 

 fact that the arrow-head was inserted by its haft and not by 

 its point, there being no indication of any perforation. For 

 this reason Baudrimont is of the opinion that the wound 

 had not been produced in actual warfare, but that in all 

 probability this was a case of surgical manipulation with 

 the object of producing some specific effect, either moral or 

 physical, similar in this respect to the system of trepanning 

 on the living subject, of which several very striking instances 

 have been brought to the notice of archa3ologists. 20 B, 

 1875. 



INFLUENCE OF TEMPERATURE ON NERVOUS SENSIBILITY. 



At a recent meeting of the Russian Scientific Association, 

 at Kasan, some results were given by Troitzky of observa- 

 tions made by himself to determine the velocity of propaga- 

 tion of the excitement produced in the nerves of frogs, by 

 galvanic currents of various degrees of intensity and of vari- 

 ous temperatures. He found that for feeble currents the 

 maximum velocity of nervous sensations is between the tem- 

 peratures -f-20 and +10 C. The velocity diminishes when 

 the nerves are warmed to 30 or cooled to zero. In strong- 

 er electric currents the influence of temperature upon velocity 

 diminishes, the velocity being affected more by the strength 

 of the current than by the temperature. In the case of very 

 strong currents the influence of temperature entirely disap- 

 pears. The velocity of transmission in the nerves depends 

 upon the strength of the excitement, increasing directly as 

 the latter. 19 #, VII., 204. 



