351 



(Nectandra rodiae) from South America and the West Indies, 

 peroba (several species of Aspidospeniia) from South America, 

 and mahogany {Swietena maliogaiii) from tropical America 

 seem to be immune from the attack of the North American 

 termites. Hagen also states that teak {Tcctoua grandis) and 

 ironwood (Sideroxylon) of India are immune from attack by 

 termites. George P. Ahern, formerly director of the Philippine 

 Bureau of Forestry, states that the following woods are not 

 subject to attack by the an^iy, a native Philippine termite: 

 Dinglas {Eugenia bract eata Roxb. var. roxhurghii Duthie), ipil 

 (Intsia bijuga Gray), molave (Vitex littoralis Dene.), and yacal 

 (Hopea plagata Vidal). In addition to these, Ccdrus deodar 

 from India, Cedriis atlantica from northern Africa, Callitris 

 glaiica (cypress pine) from Queensland, Eucalyptus iiiarguiata 

 from Australia, and Erythrophloeuin Urn from Cochin China are 

 reported to be immune from termite attack. 



As a first step in the investigatiton it was necessary to prove 

 whether these so-called immune timbers are really effective in 

 preventing termite attack or not. To do this, forty-five species 

 of native and exotic woods were selected and the test carried on 

 as follows : 



Method of investigation. — Each timber was cut into small 

 blocks of definite size, 2 by 2 by 15 inches (about 5 by 5 by 38 

 centimeters) ; hundreds of these blocks were buried in the 

 infested ground; dififerent kinds of timbers were mingled, care 

 being taken not to group the same species in one place ; from 

 time to time all the blocks wxre dug out for inspection, and 

 after eliminating the infested ones the others were buried again. 



Locality of the experiment stations. — Tainan, southern part of 

 Formosa ; and Matsubase, Kiushiu, Japan proper. 



Result of the test at Tainan. — The ground was infested with 

 Odontotermes fonnosanus (Shiraki), which is very common in 

 the southern part of Formosa. The blocks were buried on 

 November 17, 1912, and the final inspection was made on July 

 15, 1913. 



Result of the. test at Matsubase. — The ground was infested by 

 Coptotermes formosanus Shiraki. The experiment station was 

 selected in Japan proper as well as in Formosa, in order to test 

 the effect under different conditions, especially the effect by a 

 different species of termite. The blocks were buried on February 

 11, 1913, and the first inspection was made on October 8, 1913, 

 after two hundred forty-nine days. 



Although the duration of the experiment was nearly the 

 same at Tainan as at Matsubase, the results obtained were 

 slightly diff'erent. Thus, in the latter locality, kayil, palo maria, 

 and malacmalac were more seriously attacked ; lim, tallow wood, 

 iron bark, grey gum, white mahogany, supa, betis, pagatpat, 

 calantas, malugay, lanete, bansalaguin, lanutan, baniiyo, and 

 grey box were less seriously attacked; red narra, guijo, yellow 

 narra, white stringy-bark, acle, amuguis, tucang-calao, tindalo. 



