346 EASTERN ETHIOPIA xxvm 



tail is of great assistance. Darters feed as the sun 

 declines, and they are often seen in flocks. I have 

 counted twenty roosting on one tree, which, though 

 leafless, was white with their guano. 



The skill these birds exhibit in securing fish is as 

 amazing as their voracity. The size of the fish it is 

 able to swallow astonished me. On the White Nile I 

 found in the stomach of a darter three fishes, one of 

 which was as big as a herring. 



The fish-spearing habit of the darter is aided by a 

 peculiar mechanism in its neck. The first eight 

 cervical vertebrae, especially the eighth, are modified 

 and produce a kink in the neck : correlated with the 

 modification of the vertebrae are some powerful muscles 

 which enable the bird to make sudden and powerful 

 thrusts with its beak when it impales a fish. In order 

 to facilitate the retention of the fish after it is trans- 

 fixed, the edges of the darter's beak are furnished with 

 fine needle-like points directed backwards. 



The stomach of the darter contains, at its pyloric 

 outlet, a singular sieve formed of hairs developed from 

 the gastric epithelium. The lining of the stomach is 

 sometimes shed more or less completely and a new one 

 forms. 



Cormorants, insatiable fish-eaters, abound in the 

 Victoria Nyanza : they swarm on the shore of every 

 island and inlet. Around the Cascades of Jinja 

 they are present in hundreds, helping the herons to 

 whiten with their guano the rocks and trees in the bays 

 and recesses around the head of the Nile. 



It is delightful when out on the lake in a steamer, or 

 in a canoe, to see cormorants sitting on the small papyrus 

 islands which float about Kavirondo Gulf; as the 

 steamer approaches, they either fly away or dive 

 beneath the surface of the water. Some parts of the 

 Suez Canal, especially the lakes, swarm with cormorants, 

 and as the ships glide through the water these birds 

 often crowd themselves on the light-buoys : it is not 



