186 Transactions. — Zoology. 



on the wing to accomplish such a flight, its natin'al habit of resting at night 

 would cause it to perish in the water. The boldest advocate of such a theory 

 would scarcely venture to assert that a butterfly has been known to, or would 

 under any circumstances, continue its flight at night ; and if this butterfly 

 were so introduced, why not other butterflies, and the large hawk-moths so 

 infinitely stronger and swifter on the wing. The tales of clouds of butterflies 

 seen at sea, thousands of miles from land, are as unreliable as those of the sea 

 serpent. 



It is possible, but not probable, that it may have come over in some ship ; 

 that it may have entered the cabin or settled in some part of the ship, £»nd 

 having remained there during the voyage, been set at liberty in New Zealand. 



It is possible, but not probable, that ova, larvae, or pupae may have been 

 introduced with some shrub or plant. 



Thirdly. As to its introduction, either purposely or accidentally. 



Supposing the butterfly, ova, larvae, or pupae to be so introduced, it would 

 be necessary, for the propagation of the species, that the butterfly should be 

 an impregnated female ; that it should lay its eggs upon its accustomed food- 

 plant, or upon some other plant that the larvae would eat (and it is well known 

 how difiicult it is to induce the young larvae of a butterfly to accept for food 

 any other kind of plant than that upon which the larvae of a like species of 

 butterfly are accustomed to feed) ; that at least two of the larvae should escape 

 the numerous enemies and dangers to which they are subject, and attain the 

 pupa state ; that the pupae should survive, and in due time produce a perfect 

 male and a perfect female butterfly ; that such male and female should 

 copulate j and that the female should survive through all dangers until she 

 deposited her eggs upon the food plant. 



