186 Transactions.— Zoology. . 
on the wing to accomplish such a flight, its natural 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, and 
having remained there during the voyage, been set at liberty in New Zealand. 
It is possible, but not probable, that ova, larve, or pup: may have been 
introduced with some shrub or plant. 
Thirdly. As to its introduction, either purposely or accidentally. 
Supposing the butterfly, ova, larve, or pups 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 larvæ would eat (and it is well known 
how difficult it is to induce the young larve of a butterfly to accept for food 
any other kind of plant than that upon which the larve of a like species of 
butterfly are accustomed to feed) ; that at least two of the larve should escape 
the numerous enemies and dangers to which they are subject, and attain the 
pupa state ; that the pups should survive, and in due time produce a perfect 
male and a perfect female butterfly ; that such male and female should 
copulate ; and that the female should survive through all dangers until she 
deposited her eggs upon the food plant. 
