Ch. IX.] INSECTS AT SEA. 143 



operations, and the boldness with which they carried them 

 out. 



It was here, when we had stood out some 30 miles from 

 the land, that a plague of flies overtook us. The cabin was 

 so full of them that the rafters were blackened. Common 

 black house-flies, for the most part, with, however, a good 

 sprinkling of large green flies. Where they could have 

 come from was a mystery ; but they were a terrible nuisance, 

 and although we swept off hundreds in a butterfly net, their 

 numbers did not appear to be sensibly diminished. 



Another singular circumstance was, that although no 

 land was in sight, large dragon-flies repeatedly flew across 

 the ship ; and I observed a large dark butterfly flit across in 

 the direction of the land, without stopping to rest on the 

 ship. At this time the nearest land was the Chusan Islands, 

 fully 30 mUes distant. It is ' by no means an uncommon 

 circumstance to see butterflies launch themselves off one 

 shore for a short aerial excursion to the opposite shore, half 

 a mile or a mile distant, without the least hesitation ; and 

 when anchored in such a harbour, as at Ke-lxmg, they were 

 constantly flying through the rigging so rapidly that it was 

 impossible to catch them, for they never rested upon the 

 ship. Under these circumstances, they usually fly low, iii 

 a straight Kne, and near the water. 



Soon after passing through the Fisherman's Group of 

 islands, the discoloured yellow and muddy water announced 

 that we were approaching the embouchure of one of the 

 great rivers of the world, the Yang-tze-kiang. The entrance 

 is anything but imposing, the coast being perfectly flat, only 

 relieved by a few trees and sheep dotting the landscape. 

 The delta at its mouth consists of three islands, the pas- 

 sages between which are closing up, so that they will ulti- 



