100 Mr. W. L. DIstant's Geographical Distribution 



with a heterogeneous assemblage of floating molhisks, 

 small fish, crabs and other marine animals, drift wood 

 and oceanic birds, these last either dead or in a torpid 

 and helpless state on the surface of the sea. As Mr. Ben- 

 nett well remarks, this line of miscellanies on the ocean 

 denoted the termination of a current, which in its progress 

 had swept the surrounding waters of their passive or feeble 

 denizens, and had borne them thus far in a dense and con- 

 fused mass.* 



The agency of man in the distribution of this butterfly 

 is another cause which, like " winds and currents," must 

 be estimated as an efficient but only probable, or perhaps 

 possible, cause. 



In a short article by Mr. Scudderf on the introduction 

 of this butterfly into the Pacific Islands, he gives, from 

 the information of a correspondent, the fact of the young 

 larv^ being found for the first time in Ponape, of the 

 Caroline Range, feeding on some young milk weeds which 

 had just been accidentally introduced amongst some other 

 plants contained in a wardian case from Honolulu. 



Pickering, in enumerating the introduced plants of 

 Polynesia, states that within the past century, and for the 

 most part within the memory of persons now living, a 

 variety of animals and plants have been introduced into the 

 islands of the Pacific in European and American vessels. 

 He Avas informed at the Hawaiin Islands that the centi- 

 pede| was " introduced five years previously from Mazat- 

 lan." It had greatly multiplied at Honolulu, where the 

 " house scorpion" likewise abounded, and was likewise be- 

 lieved to have been imported from Mazatlan. § Mr. Bennett 

 also relates that "after we had been at sea for several 

 weeks, and even months, it was not uncommon to find on 

 board the ' Tuscan ' many birds and land insects in a living 

 state, from the hardy beetle to the delicate and more 

 ephemeral butterfly, whose germs had probably been re- 

 ceived on board together with supplies of fruit and vege- 

 tables."! There seems one objection to the theory of the 

 dispersal of D. Archippus being incidental on chance 

 dispersion of its ova on the leaves of its food plant. The 

 eggs take but a few weeks to hatch, and the young larvae 



* Whaly, Voy. Round the World, vol. ii. pp. 62—64. 



t " Psyche," vol. i. p. 81. 



j See Petites Nouvelles Entomologiqucs, No. 166. 



§ Races of Man, p. 339. 



II Whaly, Voy. Round the World, vol. i. p. 252. 



