Apbii, 7, 1911] 



SCIENCE 



533 



other words, " the amount of exudate deter- 

 mines the amount of food and the latter deter- 

 mines the development of one or the other 

 caste." It is certainly noteworthy, in this con- 

 nection, that the queen termite, in the egg- 

 laying stage, is clearly afflicted with physo- 

 gastry, a condition which, as Wasmann has 

 shown, is as characteristic of the guests of 

 termites as the possession of triehodes is char- 

 acteristic of myrmecophiles. 



In the same chapter Escherich gives an ac- 

 count of a numher of experiments on the be- 

 havior of termites brought together from dif- 

 ferent colonies. He found that alien larvae 

 are much less hostile to one another than are 

 strange imagines (workers or soldiers). As 

 would be expected, the soldiers of different 

 species differ markedly in their methods of 

 attacking and killing their enemies : the 

 Termes soldier uses its sharp mandibles as a 

 poniard or pair of scissors, the Capritermes 

 soldier as a catapult with which to toss 

 its enemies into the air; the Euiermes 

 soldier, however, pounds its enemies with 

 its cephalic horn and simultaneously smears 

 their bodies with a sticky secretion from 

 its cephalic gland; the Copioiermes soldier 

 reduces its enemy to impotence by throw- 

 ing over it a milky secretion. When termite 

 colonies are invaded by small enemies, the 

 workers often do all the fighting and the 

 soldiers slink away; but larger and more 

 powerful enemies are attacked by the soldiers 

 while the workers behave rather indifferently. 

 The main function of the soldiers is to defend 

 the nest entrances. 



Escherich is of the opinion that the nega- 

 tive phototaxis of termites has been greatly 

 overestimated, but while this may be true of 

 T. redemanni and ohscuriceps which were seen 

 building, and of E. monoceros which was seen 

 foraging " am hellen Tage im grellsten Son- 

 nenschein," the other observations cited do 

 not prove the indifference of termites in gen- 

 eral to light. Ants, too, are in the main 

 negatively phototactic, though they often 

 forage and build in the bright sunlight. 



The fourth chapter is devoted to the meth- 

 ods of exterminating termites, a matter of 



great importance in tropical countries where 

 these insects are often a serious menace to all 

 wooden structures, books, papers, cloth and 

 even to the stems of growing plants (tea, 

 cacao, etc.). The following measures are 

 recommended : first, stopping some of the main 

 openings of the nest with tow or " waste " 

 soaked with carbon bisulphide and closing all 

 the remaining openings with clay or earth; 

 second (and this is recommended as the most 

 effective treatment), the use of the "universal 

 ant-exterminator," an appliance manufactured 

 by C. Henwood & Son, of Durban. This con- 

 sists of a small charcoal stove connected on 

 one side with a hand-pump (resembling that 

 used for inflating bicycle tires) and on the 

 other with a rubber hose provided with a noz- 

 zle. On glowing charcoal in the bottom of the 

 stove a small quantity of a powder consisting 

 of 85 parts of arsenic and 15 parts of sulphur 

 is placed, the nozzle of the hose is inserted in 

 the entrance of the termitarium and the 

 poisonous fumes which fill the stove are forced 

 into its galleries and chambers by working the 

 pump. The hose is then removed, the open- 

 ings are at once plugged with clay and the 

 nest is left undisturbed for several days. If at 

 the end of a week's time some of the termites 

 are found to have survived, the fumigation 

 has to be repeated. Escherich describes an in- 

 teresting apparatus for locating termites, a 

 " Termitensucher " manufactured by Fried- 

 rich Suck, of Hamburg, for use in the German 

 colonies. This consists of a microphone in- 

 serted in a funnel at the end of a steel tube 

 and connected with a telephone receiver. 

 When the tube is stuck into the earth the 

 noise made by the crawling termites can be 

 distinctly heard through the receiver even 

 when they are working at a considerable 

 depth in the soil. By means of this apparatus 

 termites may be readily located in the tree- 

 trunks of orchards or estates or in the walls of 

 houses and marked for treatment with the 

 arsenic-sulphur fumes. 



The work closes with the following series of 

 valuable appendices by various authors on the 

 material collected by Professor Escherich in 

 Ceylon ; a taxonomic account of the Ceylonese 



