340 



THE PI.ACK OF MIMICRY 



a Ix-itesian mimic. Tiie same argument holds with ereater 

 force for the allied Precis aiitilopc in which the resemblance 

 to an Acraca is still more imperfect. 



It will be of interest at this point to exhibit in a tabular 

 form some of the remarkable series of appearances which 

 the wet forms may display in relation to the dry in the 

 great genus Precis (including yunoiia). 



S. African liabilal 

 of Species. 



Sitcics of the 

 Gciuig Precis. 



Character of Under Surface of \\ ings: 

 Hry season. Wet season. 



Forest 



\On'niiaI] 

 Woodland 



Woodland and Open 

 Open, S\vanij\v (in 

 Mashonaland) 



\ Precis iu^^'ela Procryptic rrocr\ptic 



)) 



>j 



\\'oodland 



f 

 1 



\\'oodland and Open 



elghu2 



uii/alica 

 iilmana 

 (ir/(7.\ia 



archesia 

 ' cerytu 

 ■ aclia 



antilnpc 

 ' sesamus 



I' 



Directive marks (eye- 

 spots) developed. 



Far less well concealed 

 than the dry forms. 

 Archesia I believe to 

 be Aposematic. 



Very conspicuous ; 

 roughly mimetic of an 

 Acraca type. 



The types of country alluded to in the table are as 

 follows : — Forest, with heav}' timber affording deep 

 shade ; M'oodland, without timber, trees small, affording 

 light shade ; Opoi, nothing higher than small scrub.^ 



The discover}' of the nature of the ph)siological 

 stimulus determining the two forms of Precis is a most 

 intf-rcsting problem, to which Mr. Marshall has devoted 

 an immense amount of labotir. The outcome of his 

 splendid investigations imder most difficult conditions is 

 not yet published, and therefore I will only say that the 

 results exhibit nuich that is puzzling and contradictor)-. 

 As bearing upon the problem, it may be stated that the wet 



' Dry form bred fiom wet by Marshall in i 903 : Proc. Ent. Soc,^ Loud.. 

 1906, p. Ivii. 



^ Dry form bred from wet by Marshall in 1903 : Proc. Enl. Soc, J.onci., 

 1903, J), xxxii. 



" Dry form bred from wet by Marshall in 1902: Trans. Enl. Soc, 

 Lond.^ 1902, pp. 418-20. 



* Dry form bred from wet by Marshall in 1898: Ann. Mag. Nat. 

 Hist., ser. 7, vol. ii, July 1898, p. 30. 



' Trans. Ent. Soc, Lend., 1902. pp. 423-3. 



