8o JUNGLE ISLAND 



and even then it is not altogether safe. The 

 termites prefer other wood to creosoted wood, or 

 to the very hard and heavy native woods, Hke 

 the timber of the guayacan tree, but if the near-by 

 timber becomes scarce they will work even on 

 these. Some of the wooden forms into which the 

 cement was poured to make the walls of the great 

 Canal locks were of both hard and creosoted 

 woods, but they have been attacked by termites 

 where they were left in place around the cement. 

 Probably this was because the country around 

 the locks is well cleared of wood and even small 

 bushes, and the termites there were hard driven 

 to find food. 



When we were building a wooden laboratory on 

 Barro Colorado we placed the timbers on cement 

 foundations so that no wood could come in con- 

 tact with the ground and attract a venturing ter- 

 mite scout. The laboratory was set on the top 

 of a high hill sloping down to Gatun Lake. The 

 red clay hillside was slippery enough in dry 

 weather, but after a rain it was impossible to 

 reach the top without hobnails in one's shoes and 

 a firm grasp on the strong lianas that the men 

 had tied to trees along the path. A long flight 

 of steps had to be built to the laboratory from 

 the boat landing by the Spanish-bayonet palm. 

 These rested on the ground. They were made 

 out of seasoned native timber, so hard that nails 

 could not be driven in it unless nail holes were 



