The Origin of the Markings of Caterpillars. 383 



by the small ring-spots, which might thus have 

 become repeated on all the segments (Zygophylli] . 

 In cases like the two latter, striking colours must 

 have been eliminated when inherited from an im- 

 mediate ancestor; but on this point nothing can 

 as yet be said with certainty. 



In other cases the repetition of the ring-spots 

 with strongly contrasted colours was neither pre- 

 judicial nor indifferent, but could be turned to the 

 further advantage of the species. If a caterpillar 

 fed on plants containing acrid juices (Euphorbiacece) 

 which, by permeating its alimentary system, ren- 

 dered it repulsive to other animals, the ring-spots 

 commencing to appear (by repetition) would fur- 

 nish an easy means for natural selection to adorn 

 the species with brilliant colours, which would 

 protect it from attack by acting as signals of dis- 

 tastefulness. 



But if the dark spots stood on a light ground 

 {Nicczd), they would present the appearance of 

 eyes, and cause their possessors to appear alarming 

 to smaller foes. 



From the developmental histories and biological 

 data at present before us, it cannot with certainty 

 be said which of these two functions of the ring- 

 spots was first acquired in the phylogeny, but we 

 may perhaps suppose that their significance as a 

 means of causing alarm was arrived at finally. 



It may also be easily conceived that as the ring- 

 spots became more and more complicated, they 



