EUPLOEINAE: ANOSIA PLEXIPPUS. 733 



endeavorini; to intiintain a foot hold ever since 1876 when the first instance 

 of its occurrence was recorded. The first specimen was found at Neath 

 in Soutli Wales in September, a second one in Sussex in the same month, 

 and a third at Hayward's Heath in October. In 1877 one was taken at 

 Poole Harbor. In this year also a specimen was taken upon the conti- 

 nent. It did not appear again till 1881 when a specimen was taken in 

 Kent in September. Again in 1884 one ^vas taken in the Isle of Wight. 

 In August and September, 1885, nine specimens were taken in the coun- 

 ties of Dorset, Devon, Cornwall, and the Isle of Wight. It was again 

 taken in 1886 in the south of England, in Guernsey, at Gibraltar, and in 

 Portugal. 



I have spoken of this extension of its natural region as one due to com- 

 mercial agencies, because it would seem that the distance to which the 

 insect has been carried must be due to something more than its very 

 remarkable powers of flight. The fact that the butter flyhas been seen 

 flying at sea five hundred miles from land is a sufficient proof of the lat- 

 ter, and we should be far from questioning its power to compass with no 

 very great difficulty one-half the extreme distances to which we know it 

 has been carried without power of alighting. But that this should occur 

 Avith a female heavy with eggs (and no other supposition would permit us 

 to understand its subsequent propagation in the regions visited) is past 

 credence ; more especially as we have in the instance of its transport from 

 the Hawaiian Islands to the Caroline group an almost certain proof of the 

 method of its transport, through artificial aid. The alighting of one of 

 these butterflies laden with fertile eggs upon some part of a vessel or 

 within its hold would by no means be a strange occurrence ; and this is 

 all that is necessary to explain its transport over the wider regions. That, 

 having once established itself in one of the jNIicronesian Islands, it could 

 easily spread over the whole of Polynesia through the insect's ordinary 

 power of flight will not be questioned. But that this has taken place not 

 only w^ithin historic times, but within the last twenty or thirty years, as 

 has been shown by Semper, is an almost direct proof that its first intro- 

 duction to the South Seas was by artificial means ; for if it could be brought 

 about solely by the power of flight of the insect, aided by the natural cur- 

 rents of the air, it would have happened long ago ; and the fact that the 

 insect has been able to establish itself wherever it chose when it got 

 a foot hold and that it has not until a very recent period so estab- 

 lished itself, are sufiicient proofs that commercial agencies, so much 

 more abundant in later times than formerly, have been the great means 

 of introducing these butterflies to the islands of the Pacific. It is highly 

 probable that it owed its first introduction to the Hawaiian Islands 

 to similar agencies, and that its appearance in Europe is due to the same 

 cause. 



