NORTH MELANESIA. 323 



these barriers and the islands have an average depth of from 350 to 400 fathoms. 

 But the greatest cavity yet revealed in the Melanesian waters occurs towards the 

 centre of the semi circle formed by the Bismarck Archipelago between New 

 Britain and New Ireland, where the sounding line plunged into an abyss of 780 

 fathoms. 



Climate, Flora and Fauna of North Melanesia. 



The North Melanesian lands are comprised entirely within the zone of the 

 south-east trade winds. For more than half the year, from May to September, or 

 even from April to November or December, the wind sets steadily in the normal 

 direction ; then it yields to the west or north-west monsoon, a variable and 

 shifting current, but still humid, like the trade wind, for it also traverses a wide 

 expanse of water before reaching the islands. Hence there is at least one rainy 

 day in three, at times one in two, throughout the year, and both the Bismarck and 

 Solomon Archipelagoes have a mean annual rainfall of not less than 150 inches in 

 the immediate vicinity of the seaboard,* and far more on the higher slopes where 

 the moisture-bearing clouds are first intercepted. According to Guppy, the 

 discharge averages from 4-40 to 480 inches at heights of 6,000 to 7,000 feet in 

 the upland valleys of Guadalcanar facing towards the south-east trades. These 

 mountain slopes appear to be the most copiously watered of any oceanic lands, and 

 are elsewhere surpassed in this respect only by the escarpments of the Khasi Hills 

 in the Brahmaputra basin. During a single downpour of ten hours Guppy 

 recorded over 11 inches of rain in the neighbourhood of the coast. The least 

 healthy season is that of the variable winds accompanying the west monsoon. 



Thanks to the abundant rainfall, the North Melanesian flora, which greatly 

 resembles that of New Guinea, is both rich and varied. Even the low coral banks 

 disappear in many places under the large trees, the seeds of which have been brought 

 by the winds, the marine currents, and the birds. On the hillsides the forests 

 extend in a continuous, impenetrable mass, their leafy canopies rising here and 

 there over 150 feet above the ground. One of the most widespread of the^e foreign 

 growths is the banyan fig, with its thousand pendent tendrils twining round and 

 at last choking other species. This incessant struggle between the banyan and the 

 other giants of the woodlands forms a familiar theme of many local legends. 



One of the most remarkable products of the cryptogamic flora in the Solomon 

 group is a mass of vegetable matter which resembles the yam, but which is found 

 resting upon the ground without roots or any connecting stems. Guppy dwells 

 with admiration on the surprising knowledge displayed by the natives in 

 botanical matters. They clearly distinguish between species almost identical in 

 appearance, and in this respect show themselves far better naturalists than any 

 educated Europeans except specialists. 



The North Melanesian fauna also greatly resembles that of New Guinea, but 



* Rainfall at Santa- Ana off south-east coast of San Cristobal in 1883, 125 inches; at Ugi, east of 

 San Cristobal, 146-24 inches.— (Guppy). 



