422 PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. [Dec. 2, 



Such glands have not yet been detected in our Anosia plexippus. 

 In this as in other butterflies the slightly disagreeable taste or smell 

 is probably due to the pigment in the scales of the wings. The 

 lepidotic acid of Gonopteryx rhamni is thought by Hopkins to be 

 repellant to birds. ^ 



It is well known that Arctia virgo, Leu care tia aercBa, Spilosoma 

 vtrghtiea, Pyrrharetia Isabella, etc., secrete in eversible abdominal 

 glands a rank, bad smelling odor which, as we have observed, is 

 like that of laudanum. Yet these moths have no mimics, and only 

 one of them, the Arctia, has warning colors. A few of the Synto- 

 midas and Zyggenidae are known to emit a disagreeable odor, 

 as the species of Zygaena, but on tasting bits of the abdomen of a 

 female Ctenucha vh-giniea I was unable to detect any unpleas- 

 ant taste ; on offering one to a parrot it seized it, but let it drop 

 and did not eat it. I do not, however, regard this experiment as a 

 satisfactory one, as the bird may have been frightened by my 

 attempts to hand the moth to it. 



Mimicry due to convergence. — It is plainly evident that the 

 Batesian, and more especially the Miillerian, hypotheses rests on an 

 insecure basis and will have to be abandoned, and that the phenom- 

 ena of mimicry should be attributed to convergence ; certainly not 

 primarily to the biological environment, i.e., to the fancied struggle 

 for life with insectivorous birds. 



That protective mimicry is due to convergence is denied by Mr. 

 Marshall.* In stating the case of Papilio leonidas of Mashonaland 

 and Delagoa Bay, with its ''strong and rapid flight," in contrast 

 with the " slow sailing movements " of its southern parallel variety 

 drassides, *' to show off its coloration which is so characteristic of 

 the protected Danainae and Acraeinae," he does not attribute the 

 difference in these two varieties to simple climatic or local causes, 

 but to adaptation by mimicry owing to the abundance of its model 

 ^w^f/m ^^//^r/^, adding : " It does not seem to me that conver- 

 gence would explain the facts, for if leonidas is itself protected it 



"^Phil. Trans. Roy. Soc. London, 1895, pp. 661-682. See also Packard's 

 Text-book of Ento?nology, p. 206. 



' Five years' observations and experiments (1896-1901) on the bionomics of 

 South African insects, chiefly directed to the investigation of mimicry and vi^arn- 

 ing colors, by Guy A. K. Marshall. With a discussion of the results and other 

 subjects suggested by them, by E, B. Poulton, etc., Ttans. Ent. London, 1902, 

 P- 507. 



