VARIABLE PROTECTIVE RESEMBLANCE IN INSECTS 115 



naturalists would have been brought to bear upon the 

 subject. The experiment, however, was not made till 

 nineteen years later, when I was led to do as Mr. 

 Wood had proposed, although unaware at the time of 

 his suggestion. 



Nevertheless, during these nineteen years, gradual 

 confirmation of Mr. Wood's central position was 

 afforded. In 1873 Professor Meldola supported the 

 observations upon the chrysaHdes of the 'Garden 

 Whites.' He compared large 

 numbers of individuals, and 

 found that the pupae upon 

 black fences were darker 

 than those upon walls. ^ 



In 1874 a paper by Mrs. 

 M. E. Barber, and commu- 

 nicated by Mr. Darwin to 

 the Entomological Society 

 of London, was printed in 

 the Transactions of that 

 society. 2 Mrs. Barber had 

 experimented with a com- 

 mon South African Swallow- 

 tailed Butterfly (Papilio 

 nireus), and had found the 

 chrysalis wonderfully sensi- 

 tive to the colours of its environment. When the 

 pupae were attached among the deep green leaves of 



> Zool. Soc. Proc. 1873, p. 153. « 1874, p. 519. 



Fig. 25.— The pupa of Papilio nireus 

 attached to orange tree; natural 

 size. 



