paper all were dusky with much spotting of dark brown, so 

 were seven out of eight on dark sticks, the eighth being 

 green. Of twelve on green cabbage leaves or on the glass of 

 the bottle containing them the majority were green or 

 greenish ; seven out of eight of those on yellow paper, and all 

 the eleven on orange leno were green ; of seven in absolute 

 darkness six were green, two much spotted with dark brown, 

 one bone-coloured with much spotting. He also exhibited 

 28 pupae of P. brassicce and about 40 of P. rapce, with results 

 in accordance with those obtained and recorded by Prof. 

 Poulton. In the case of both these species he had some con- 

 fined during the whole period of susceptibility to clear glass, 

 with no substances near that reflected any colours or white or 

 black ; the results very nearly resembled some kept in absolute 

 darkness, except that those on the clear glass were a little 

 darker. One very interesting napi exhibit was that of the sheet 

 glass roof of a breeding cage in two compartments, one having 

 the interior partly orange and partly yellow, the other black; in 

 the orange-yellow compartment 46 had pupated on the roof on 

 which orange leno had been placed, transmitting orange light, 

 and all but four of these were green with very little dark 

 spotting ; in the other compartment 34 had pupated on the 

 glass roof which had been covered outside with opaque black 

 paper and all of them were bone-coloured, most of them much 

 spotted with dark brown. He thought it was impossible to 

 doubt that much of the colouring was protective. 



Mr. Bateson said that he had lately bred P. oiapi on a large 

 scale, and as regards that species he could quite confirm 

 Mr. Merrifield's observations. His own experiments had been 

 undertaken with a different object, but he had frequently 

 noticed that there was a fairly close correspondence between 

 the colour of the pupse and that of the substances to which 

 they were attached, though exceptions to this rule were not 

 uncommon. He had moreover observed that in this respect 

 there was considerable difference between different families of 

 larvse. In his experiments the offspring of each pair wei'e 

 kept separate, and in some families many larvse pupated on 

 the food plant, while in others scarcely any did so. In some 

 families the pupal colours conformed in nearly every case, 



