PHOSPHORESCENCE 491 



wooden trunk. On the Tanganyika plateau I have camped on ground which 

 was as hard as adamant, and as innocent of white ants, apparently, as the 

 pavement of St. Paul's, and awakened next morning to find a stout w^ooden 

 box almost gnawed to pieces. Leather portmanteaus share the same fate, 

 and the only substances which seem to defy the marauders are iron and tin." 



The following extracts give an idea of how the work of the white ants 

 looks from the point of view of the civil engineer :^^ 



"The forests contain some varieties of hardw^oods which would be suitable 

 for permanent structures were it not for the ravages of insects. A species of 

 white ant, called locally 'cupim,' appears to be the most destructive. These 

 insects seem to attack timber bridges more than they do the timber ties, w^hich 

 are partially buried in the ground. They work in armies, building nests and 

 artificial tunnels on the outside of bridge timbers and working into the heart 

 of the timber from the ends. Although the largest of the 'cupims' yet observed 

 is no longer than i/4 inch, so rapid and destructive is their action that the life 

 of a timber bridge can hardly be considered more than two years. Frequently 

 stringers and timbers whose ends butt together, appearing perfectly sound on 

 the outside, are found in an incredibly short time to be so thoroughly honey- 

 combed by this energetic little creature as to become unsafe members in a 

 bridge or other important structure. No satisfactory method of preventing 

 the action of the 'cupims' has yet been found here. Kerosene poured over a 

 nest or into a tunnel will kill the insects within. The timber can then be 

 scraped clean, but another army is soon at work again. 



"Timber bridges have been built at various places to expedite the work and 

 get the rail head to the front, but for permanency steel and masonry are the 

 only materials suitable. A considerable quantity of pine lumber from the 

 Southern States is being used for building purposes in Porto Velho. The ex- 

 perience up to date indicates that the insects do not attack this resinous wood, 

 but not sufficient time has yet elapsed to prove conclusively that pine lumber 

 will withstand their ravages. Ties of native lumber used in the track, either 

 on account of the vibrations of passing trains or the partial covering of earth, 

 resist the 'cupinr more successfully." 



It should be noted that although the white ants are abundant in for- 

 ests, I am not aware that they ever attack the living trees. Thev appear 

 to eat only the dead trunks or dead limbs or bark. Many of them build 

 their nests on the trees, ^ests fonnd high up on tree trunks are always, 

 so far as I have observed, made of woody matter and not of earth. Those 

 on trunks, only a meter or two above the ground, are often made partly 

 of woody matter and partly of earth. 



PHOSPHORESCENCE 



It has been stated that some of the termites are luminous. On this 

 subject see notes by Frederick Knab, Science, vol. xxx, October 22, 1909, 



56 ,Tohn Y. Bayliss : The Madeira-Mamore Railway. Engineering News, vol. Ixli, p. 454. 

 New York, October 28, 1909. 



