Ocmrrencc of a South American Butterfly in Britain. 163 



treme quiescence of the pupa is in reality only a prolongation 

 of the quiescence accompanying every change of skin, and this 

 prolongation is due to the great amount and rapidity of the 

 changes going on in it. In those insects whose metamor- 

 phosis consists principally of a mere increase of size and the 

 acquirement of wings, there is no stage corresponding to the 

 pupa of butterflies and moths. In others whose changes are 

 more extensive, the pupa, though at first inactive, gradually 

 acquires activity. On the other hand, in those insects, as 

 Lepidoptera, in which not only does the external form but also 

 the whole internal organisation undergo change, there is an 

 inactive pupa ; still even these pupse have some power of 

 motion, and this power is greatest shortly before they make 

 their final change. A great clue to this difference is to be 

 found in the structure of the mouth. In those insects in 

 which the mouth and digestive organs are the same through- 

 out life, the changes which occur are slight and very gradual, 

 so that there is no marked period of quiescence. On the other 

 hand, in those insects, as Leimloiotcra, in which the insect has 

 an entirely different method of feeding when a larva from 

 what it has when perfect, the changes, if gradual, would 

 necessitate the death of the larva ; so they are compressed, as 

 it were, into one stage, which stage is therefore necessarily 

 inactive. 



III. 0)1 the Occurrence of a South American Butterfly in 

 Britain, (Specimen exhibited.) By John Gibson, Esq. 



In July 1871 Mr Gibson Carmichael observed a butterfly 

 on the roof of one of the carriages of the London and South- 

 western Railway shortly after leaving Wokingham station. 

 He captured it and placed it in his cabinet as a variety of the 

 Painted Lady {Pyrameis carclui), but subsequently he was led 

 to think that it agreed more closely with a North American 

 species nearly allied to our Painted Lady, viz., the Fyrameis 

 Himtera. On sending it to an entomologist in London, it was 

 found, on comparing it with the specimens in the British 

 Museum, to be the Brazilian variety of the Pyrameis Huntera 



