1904.] PACKARD— ORIGIN OF MARKINGS OF ORGANISMS. 417 



to insect enemies." And then after stating that they all have a 

 peculiar smell, he mentions almost incidentally : '' I never saw the 

 flocks of slowly-flying Heliconidas in the woods persecuted by birds 

 or dragon flies, to which they would have been an easy prey ; nor, 

 when at rest on leaves, did they appear to be molested by lizards or 

 the predaceous flies of the family Asilidse, which were very often seen 

 pouncing on butterflies of other families." Here it may be added 

 that Bates nowhere states that he ever saw a bird pursuing or 

 devouring a butterfly, and does not dwell on this subject, beyond 

 remarking (on p. 499) that the Heliconidse " show every sign of 

 flourishing existence, although of slow flight, feeble structure, 

 unfurnished with apparent means of defense, and living in places 

 which are incessantly haunted by swarms of insectivorous birds." 



Bates' explanation of the origin of mimetic species is by natural 

 selection, although he says : "In what way our Leptalis originally 

 acquired the general form and colors of Ithomi^ I must leave 

 undiscussed." He suggests, however (p. 512), that the selecting 

 agents are insectivorous animals, which gradually destroy those 

 sports or varieties that are not sufficiently like Ithomi^ to deceive 

 them." He also says : " The conditions of life of these creatures 

 are different in each locality where one or more separate local 

 forms prevail, and those conditions are the selecting agents." 



Bates' discussion of this subject is broad and sound, due to his 

 observations over wide regions of country, and to careful studies on 

 his return to England. He was evidently impressed with the fact 

 that local varieties arise from local conditions of the environment, 

 and does not entirely rely on the attacks of insectivorous birds ; in 

 this respect he is less narrow than later writers on mimicry, allow- 

 ing as he does, and even seeming to waver between, the modifica- 

 tions due to changes in the physical conditions and the action of 

 insectivorous birds alone. 



How Mr. Bates regarded the subject seventeen years later may be 

 seen by his comments on Miiller's theory, made at a meeting of the 

 Entomological Society of London in June, 1879 {^Trans., p. xxviii), 

 which we quote on p. 419. 



Here might be cited the statement of another naturalist. Dr. 

 Seitz,^ who found in a forest of southern Brazil a perfectly circum- 

 scribed region in which the insects were almost entirely blue ; a few 



^ Zoolog. JahtbiUher, V, p. 317, 1S90. Quoted by Beddaid, "Animal 

 Coloration," p. 46. 



