116 MK. J. S. l5UDaETT ON THE 



part, in the wet season, is completely under water. On the highest part of the island 

 is the native town of Ginginberri, and the ruins of the old military settlement 

 where I lived. The eastern half of the island is partly under cultivation, and here 

 the natives plant rice on the low land, and kuskus or millet on the high land. The 

 western half of the island is little cultivated, and here was ray hunting-ground. 



The whole island is traversed by one main swamp, which has the appearance of 

 having been at one time an old bed of the river, and which is seldom quite dry, even 

 in the dry season. Parallel with this lie several shallower and more irregular swamps, 

 all of which become perfectly dry in the dry season. These swamps are separated by 

 belts of low forest, composed largely of leguminous trees, palms, and fig-trees. The 

 swamps themselves are mostly choked with papyrus and other swamp-grasses ; while 

 in the middle there is often a little open water covered with several kinds of lovely 

 water-lilies. 



The amount of open water depends largely on the rapidity of the oncoming of 

 the rains. In the present season there was little open water, as the rains came on 

 very slowly and gave the grass time to grow abundantly. 



As the rainy season advances the swamps become filled with water, the river rises 

 and soon becomes connected with the swamps by narrow creeks, up which great 

 numbers of fishes pass to the flooded grasslands to spawn. Conspicuous amongst these 

 are the two species of Polyptenis — P. lapradei Steind. and P. senegalus Cuv. 



II. — Results of the Search for Polypterus Eggs. 



From what I observed in my former expedition of its habits, I concluded that the 

 eggs of Polypterus might be obtained by one of three methods : — 



(1) Hunting the flooded grasslands for the eggs in a state of nature. 



(2) Inducing Polypterus to breed in captivity. 



(3) Artificially fertilizing the eggs of the female. 



The first method was persistently tried without success, especially on the occasion of 

 spawning females being brought in, when, taking a number of natives to the spot, we 

 examined every foot of water within a hundred yards of the place where the female 

 had been caught. Five spawning females were caught, but in no case did I find a 

 single egg. 



For the purpose of the second method I took out to the Gambia with me a large 

 number of wire hurdles, with which I made four enclosures in the swamp. During 

 the second half of June about fifty Polypteri were caught in pools by the river-side. 

 As the rains had scarcely begun, and consequently there was no water as yet on the 

 land where I had made my enclosures, I temporarily turned my fish into large 

 floating cages in the river, and fed them regularly on minced meat. A few days after 

 turning them in, I came one evening to feed them, and found that the two cages 



