NIGERIA 167 
many failures owing to experiments on bad soil and seasons of 
extreme drought, the growth of the trees gives the greatest promise 
of mature trees, or at any rate merchantable trees, being grown in a 
comparatively short period. Plantations have also been made at 
Awka, Udi, Okwoga and Ida. 
Already on the old town site of Ijaiye, mahoganies have been seen 
over 6 feet in girth which have grown up from self-sown seedlings 
within a period of about sixty years. The soil in this locality is none 
too good, and the rainfall on the average certainly does not exceed 
50 inches per annum. Near 47 Benin villages small communal 
plantations of mahogany have been made. 
All the mahoganies apparently, especially when grown in “ pure ” 
plantations, are attacked by a leading-shoot borer, which so weakens 
the leading shoot as to make it fall off, and the tree subsequently 
grows with two leaders. Later on this forms a large fork in the tree, 
which, when the time comes for felling, is by no means to be despised, 
forming as it does usually a very good “curl.” In other respects it 
is disadvantageous in reducing the length of the single straight bole. 
In this manner it has the effect of reducing the number of logs of long 
length and even shape and large size that can be obtained in one tree. 
In many cases, a log can be cut above from each limb forming 
the fork; but of course these are both much smaller than those from 
the bole, and are usually not nearly so straight, and one or other of the 
limbs is liable to be broken when the tree is felled. In the original 
forest. only isolated trees are attacked by this leading-shoot borer, 
whereas in a plantation nearly all the trees suffer by its depredations. 
Various species are being tried for admixture with the mahogany 
in order to hinder the spread of the attacks. At Olokemeji there 
is a mahogany plantation largely interplanted with two species of 
Mimusops multinervis and Mimusops Elengi. So far this appears 
most suitable, as the soil is kept thoroughly covered by the dense 
shade cast by the Mimusops, and there is a very considerable space 
between each mahogany-tree. However, the mahogany grows faster 
than the Mimusops, so that after the first few years it does not have 
so much effect. Even so, it tends to keep the bole of the mahogany 
clean and the state of the soil in mechanical and physical condition 
such as to be most conducive to the growth of mahogany. 
A mixture occasionally seen in nature has yet to be copied—that 
of mahogany and Chewstick (Anogeissus levocarpus). To some extent 
it is seen at Olokemeji, where the self-sown seedlings have come up 
in a mahogany plantation, but of course they were rather too late to 
effect the result, ie. protecting the mahogany from the leading-shoot 
borer. At Ilaro a most typical Mahogany Reserve, an isolated planta- 
tion made amongst secondary growth, has more than held its own 
with little or no tending after the first two years, and yet the trees 
