Literary Notices. clxxix 



more sensitive to temperatures below its own surface temperature than 

 to temperatures above it. The skin is most sensitive to changes of 

 temperature near its own zero point. 



In five subjects hot spots and cold spots were mapped out in se- 

 lected areas from all of the bodily regions. The parts of the body 

 most sensitive to cold do not contain a greater number of cold spots 

 than other parts. Again, contrary to Goldscheider's claims, the parts 

 most sensitive to heat frequently had no more hot spots than other 

 parts. It was proven that hot spots when stimulated with cold gave a 

 sensation of cold; and the cold spots when stimulated with heat gave 

 a sensation of heat. There are therefore not two separate sets of end- 

 organs for heat and cold. This accords with Dessoir and not with 

 Blix and Goldscheider. 



The reaction time to heat and cold was studied in ten subjects. 

 This time varies with the temperature, with the part of the body 

 tested, with the conductivity of the skin to heat, and with the con- 

 ductivity to heat of the instrument used in making contact with the 

 skin. Whatever increase in the reaction time to heat or to cold there 

 may be over the reaction time to touch, is due mainly, if not entirely, 

 to the time occupied in raising the temperature of the skin in one 

 instance, and lowering it in the other, to a point sufficiently far from 

 the normal to produce a stimulation. 



Play in the Lower Animals. 



Dr. Jas. Weir, Jr., contributes some interesting observations on 

 the Habit of Amusement in the Lower Animals to the October num- 

 ber of The American Naturalist. He writes, " I have seen, in actino- 

 phorous rhizopods, certain actions, unconnected with sexual desire or 

 the gratification of appetite, which lead me to believe that these mi- 

 nute microscopic organisms have their pastimes and moments of sim- 

 ple amusement. On several occasions while observing these crea- 

 tures, I have seen them chasing one another around and around in 

 their minature sea. They seemed to be engaged in a game of tag. This 

 actinophrys is not very agile, but when excited by its play, it seems 

 to be an entirely different creature, so lively does it become. These 

 actions were not those of strife, for first one and then another would 

 act the pursuer and the pursued. There were generally four or five 

 actinophryans in the game. One of the rotifers frequently act as if 

 engaged in play. On several occasions I have observed them per- 

 form a kind of dance, a pas seul, for each rotifer would be alone by 

 itself. Their motions were up and down as if exercising with an in- 



