TANGANYIKA (1) 135 
building the botanist could be seen surrounded by plants that he 
had gathered recently on an expedition, arranging and classifying 
them; but most intriguing to me was the laboratory where a fel- 
low was testing the tensile strength of sisal fibers with a home- 
made “Heath Robinson” apparatus that worked splendidly. In 
front of this sat a trained native who gave each fiber an index 
number which, with its pedigree, was duly entered in a book, and 
to this was added the all-important breaking strain. Years of 
patient research with crops grown on the station have enabled 
those concerned to evolve varieties of sisal that grow quicker, give 
a greater yield, and produce stronger fibers, and so benefit, in no 
small measure, the important sisal-growing industry of the East 
African Territories. 
The forest around Amani (3,000 feet) was luxurious and proved 
difficult for collecting live specimens as many of the interesting 
species were confined to the forest canopy, and even the capture 
of lower-level birds was an exhausting business owing to the 
humid heat and the steep slippery slopes of the forest bed. 
The most conspicuous birds were the grotesque-looking Silvery- 
cheeked Hornbills—a black-and-white species somewhat larger 
than the Trumpeter Hornbill, which was also present in the dis- 
trict, but in much smaller numbers. These larger hornbills, known 
locally as Hondo-hondos, make their presence known not only 
by their incessant cries as they feed on berries in the tree-tops, but 
by the loud swishing noise of their wings when in flight. 
In nature one is forever coming across creatures with unusual 
habits and here at Amani, besides the hornbills, the Palm Swifts 
provided a good example of the ingenuity or adaptiveness in the 
matter of nesting. These birds’ nests are placed out of reach of 
most of their natural enemies, as they are always attached to the 
mid-rib of a leaf of the dracaena or other palm, according to 
locality. These leaves wave so violently in any breeze that it is 
evident that some unusual nesting-habits must have been evolved 
to survive such conditions. This is so, for the Palm Swift has 
solved the problem by laying one or two eggs and by sticking 
them with saliva to the nest. The latter has no depth at all and is 
merely a pad comprised of agglutinated saliva into which are 
woven feathers or fibers, and it is to the latter that the egg, or 
