THE AFRICAN RUBBER TREE 173 



that by using this system it may be possible to tap 

 the trees two or three times a year without diminishing 

 the yield. Similar trials made on trees growing in tlie 

 native communal plantations in the Benin City district 

 of Southern Nigeria did not give such satisfactory re- 

 sults, however, so far as the healing of the incisions was 

 concerned, and it is evident that fmther observations 

 on the point are necessary. The possible effect of the 

 pricker in producing excrescences of the wood, as in the 

 case of Para trees, will also have to be borne in mind, 

 as it may not become apparent for some time. 



CliTLsty has recommended a method of tapping Fun- 

 tumia trees which he describes as the double half-spiral 

 system. It is a double-herringbone system over the 

 whole stem, the lateral cuts being made 8 in. apart and 

 extending round half the circumference. In retappmg, 

 fresh lateral incisions are made from 1^ to 2 in. above 

 the old cuts and a new vertical channel is also cut at 

 the side of the first. He states that incisions made with 

 the groover and pricker heal rapidly, and that if the 

 trees are tapped two or three times a year by the above 

 method, the renewed bark will be ready for retapping 

 by the time the bark between the first lateral cuts has 

 been used up. This method is said to give fair yields 

 of latex regularly year by year with the least possible 

 injury to the tree. 



A system of vertical incisions has also been tried in 

 the Cameroons for tapping Funtiimia elastica. In this 

 method two or more parallel vertical cuts are made in 

 the bark, extending from the foot of the tree to various 

 heights, and the latex is collected at the base. Some- 

 times shallow grooves are first cut in the bark, and the 

 latex is then liberated with the point of a pruning-knife. 

 Subsequent incisions are made at the side of the previous 

 cuts. This method gives a very fair yield of latex, and 

 the results of experiments made with it in the Gold Coast 

 and Southern Nigeria will be found on pp. 178 and 180. 



A number of well-known tapping tools, designed 

 specially for the Para tree, have been tried in Southern 

 Nigeria for Funtumia elastica, but it Is stated that besides 

 Christy's knife and pricker, only the '' Para," the 

 " Secure," the " Sculfer," and Messrs. Walker and 

 Sons' knives were at all suitable for the purpose. 



