256 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1936 



the fern Asplenium sandersonii, Piper capense, representatives of the 

 tribe Helianthoideae of Compositae, and a species of Acalypha 

 (Euphorbiaceae) . 



(2) Owing to a lack of what apparently are normal food constitu- 

 ents the gorilla has become more enterprising in search of food, and 

 in consequence climbs trees freely to a known height of at least 50 

 feet. Further reference to this is made later. 



(3) The "beds" of the Kayonsa gorilla are large platforms built in 

 the trees, and often at a considerable height above the ground. The 

 subject of these "beds" will be dealt with more fully in due course. 



Finally, in connection with divergence is the question of habitat, 

 which is really the crux of the situation, for nowhere does it exceed 

 8,000 feet in height, the altitude varying between 6,000 and 7,900 feet. 



Little is known of the greater part of the area marked on the map 

 "Impenetrable forest", as there is no population and no means of 

 access. On the hill and ridge tops, once attained, progress is fairly 

 simple along the numerous paths made by the gorillas and bush-pigs, 

 but abrupt climbs up the hill slopes, sometimes for 1,000 feet and 

 over, and passage through the dank valleys choked with dense under- 

 growth is only possible if a file of the local populace armed with 

 home-made billhooks, an indispensable of their everyday equip- 

 ment, lead the way. There are some stands of fine trees, particularly 

 noticeable being a species of Podocarpus^ at the higher elevations; 

 but, on the whole, except for here and there a forest giant of out- 

 standing size, the timber is disappointing and, in the portion (the 

 southern) of the forest visited, suggestive of comparatively recent 

 origin. 



The various photographs of the forest give an accurate idea of its 

 grandeur, density, and beauty. To obtain these pictures it was neces- 

 sary to fell several trees and clear away large patches of secondary 

 growth to afford an uninterrupted view of the opposite hillslope. 

 The densely tangled undergrowth, securely bound and interwoven 

 with brambles and a variety of tough creepers, for man is absolutely 

 impenetrable, but through it a 6-foot gorilla weighing 400 pounds 

 creeps with ease and without making a sound. One of the photo- 

 graphs reveals a scarcely perceptible hole in the tangled vegetation 

 below the tree-ferns through which, not long before, a full-sized 

 male gorilla had emerged silently and unexpectedly upon two Euro- 

 pean prospectors : both parties were equally surprised ! 



The great feature of this forest region is the abundance of graceful 

 tree-ferns; many are fully 20 feet in height, while a few reach the 

 amazing height of 30 feet. As this region constitutes neither tropical 

 nor rain-forest but can be described as typical montane forest, the 

 tree-ferns are to be found in their luxuriant abundance principally 



