January 7, 1910] 



SCIENCE 



25 



the state of Minas Geraes. This material 

 shows no signs of luminosity at present, 

 though it does not follow, of course, that it 

 never was luminous. 



The following note which I translate from 

 " Viagem ao redor do Brazil," 1875-1878, pelo 

 Dr. Joao Severiano da Fonseca, Eio de Janeiro, 

 1880, page 353, is much more to the point: 



On the head waters of Rio Verde (state of 

 Matto Grosso, Brazil) we saw one night a sur- 

 prising sight. One of the white ants' nests seemed 

 to be covered with little lights, and these tiny 

 stars made it look like a miniature tower bril- 

 liantly illuminated. It was near the tent of 

 Captain Craveiro, the commander of the troops, 

 and that gentleman invited us to share his sur- 

 prise and pleasure. When the nest was struck 

 with a stick the miniature lights went out as if 

 by enchantment, but only to reappear again little 

 by little, beginning where the blows had been 

 weakest. 



I know but one other reference to this phe- 

 nomenon in the works of Brazilian travelers, 

 and that is the following brief note given in 

 Oastelnau's " Expedition dans les parties cen- 

 trales de I'Amerique du Sud, Histoire du 

 Voyage," Paris, 1850, Vol. II., p. 103. In 

 describing the travels in the neighborhood of 

 the city of Goyaz the author says : 



On the night of the fifteenth in the vicinity of 

 the Agoa Limpa estate we noticed a luminous 

 mass in the middle of the campo that aroused our 

 curiosity greatly. On approacliing it we found it 

 to be a termites' mound from which shone a great 

 number of small points of light [petits foyers 

 lumineux]. This phenomenon is produced by the 

 presence of an immense number of small phos- 

 phorescent larvae which withdrew into the gal- 

 leries they had built when one tried to capture 

 them. 



The fact that I have lived and traveled in 

 Brazil for ten years without ever having seen 

 this luminosity at all; the surprise of Dr. 

 Severiano da Fonseca at seeing a single in- 

 stance in Matto Grosso; and the note by 

 Castelnau, who traveled through tropical 

 South America for four years, all lead me to 

 surmise that this luminosity is probably con- 

 fined to some particular species, or possibly to 



some special occasions or conditions of ter- 

 mite life. J. C. Bhanner 



StaNFOBD XjNIVEEfetTY, CAL., 



December 13, 1909 

 '•' CORRELATIONS OF CLIMATIC CHANGES 



Having taken into consideration the yearly 

 mean temperatures of 1891 to 1900, from all 

 available sources, and after having discarded 

 all doubtful records, I have drawn maps rep- 

 resenting the geographical distribution of an- 

 nual departures from the normal tempera- 

 tures, the means of the ten years' observations 

 being considered as normal values. On those 

 annual maps I call thermopleions, or simply 

 pleions, the areas occupied by positive depar- 

 tures, antipleions those of negative departures. 

 The pleions and antipleions are bounded by 

 the quasinormal line. 



On this line the departures are nil, the 

 values being equal to the ten-year means. 



The lines of equal positive and negative 

 departures I call hypertherms and hypotherms. 

 The pleions represent inflections of the iso- 

 thermal lines towards the pole, or, more prop- 

 erly speaking, towards the regions of colder 

 climate. 



The antipleions, on the contrary, character- 

 ize a local abnormal descent of the isotherms 

 towards the equator. 



The maps of successive years, for the same 

 country and those of diiierent countries for 

 the same year, show remarkable correlations 

 in the distribution of the departures. 



A pleion, in most cases, exists during sev- 

 eral years, moving from place to place. When 

 one compares the different maps, and espe- 

 cially those of European and Asiatic Russia, 

 one is led to believe that the pleions are pro- 

 duced by immense waves intercrossing. It 

 seems that for the whole world, the years are 

 either too warm or too cold following the pre- 

 dominance of pleions or antipleions. For ex- 

 ample, the year 1893 was exceptionally cold, 

 1900 on the contrary was too warm. The 

 temperature of the earth's atmosphere was at 

 least one half a degree Centigrade higher dur- 

 ing the year 1900 than during 1893. It is a 

 notable fact that neither the Alps, the Cau- 

 casus nor the Rocky Mountains form barriers. 



