510 MR. H. W. BATES ON THE LEPIDOPTERA 



I think it will be conceded that all these various kinds of imitative resemblances belong 

 to the same class of phenomena, and are subject to the same explanation. The fact of 

 one species mimicking an inanimate object, and another of an allied genus a living 

 insect of another family, sufficiently proves this. I do not see how they differ from the 

 adaptations of organs or instincts to the functions or objects they relate to. All are 

 ada])tations, either of the whole outward dress or of special parts, having in view the 

 welfare of the creatures that possess them. 



Every species in nature may be looked upon as maintaining its existence by virtue of 

 some endowment enabling it to withstand the host of adverse circumstances by which 

 it is suri'ounded. The means are of endless diversity. Some are jirovided with special 

 organs of offence, others have passive means of holding their own in the battle of life. 

 Great fecundity is generally of much avail, added to capabilities, active or passive, of 

 widr dispersion ; so that when the species is extirpated in one part of its area of distribu- 

 tion, llie place is refilled by migration of individuals from another part. A great number 

 ha\ (• mt'ans of concealment from their enemies, of (me sort or other. Many are enal)led 

 to escape extermination, or o1)tain subsistence, by disguises of various kinds : amongst 

 these must ])e reckoned the adaptive resemlilance of an otherwise defenceless species to 

 one Avhose flourishing race shows that it enjoys 2)eculiar advantages. 



"What advantages the Rel'icnnhhe possess to make them so flourishing a group, and 

 consequently the objects of so much mimetic reseml)lance, it is not easy to discover. 

 There is nothing ajjpareiit in their structure or habits which could render them safe 

 from persecution l)y the numerous insectivorous animals which are constantly on the 

 \\'atch in the same parts of the forest which they inhabit. It is probable they are un- 

 jinlatable to insect enemies. Some of them {Liicorea, Ituna) have exsertible glands near the 

 tiiuis, which are protruded when the insects are roughly handled ; it is well known that 

 similar organs in other families [Carahidce, Slcq^Iii/liuidu') secrete fetid liquids or gases, 

 :ni(l serve as a protection to the species. I have noticed also that recently killed speci- 

 minis of Danaoid Ilellcoi/ida; when set out to dry, were always less subject than other 

 insects to 1)e devoured by vermin. They have all a peculiar smell*. I never saw the 

 flocks of slow-flying HeUroiiidcc in the woods jiersecuted by liirds or Dragon-flies, to 

 w liicli they would have been easy prey ; nor, when at rest on leaves, did tliey appear to 

 l)e molested l)y Lizards or the predacious Flies of the family Asiliihr, wliicli were very 

 ofieii seen pouncing on ]3utterflies of other families. If they owe their flourishing ex- 

 islciice to this cause, it would be intelligible why the Leptalidte, whose scanty number 

 of individuals reveals a less protected condition, should Ik- disguised in their dress, and 

 lliiis share their imm\mity. 



This explanation, liowever, would not apply to the imitation of Danaoid JL-rtcoiiidcc 

 1)V ollici- species of the same subfamily. IMoreover, there are several genera of otlier 

 groups {<•. //., Ilclico/ntfti, Piipilio) which contain mimetic species side l)y side with species 

 tiiat are the objects of mimicry by mcmliers of other families, as w ill lie seen by reference 

 to the Table at p. .50;^. There is lU) reason to coiu-lude that some of these possess the 

 peculiar means of dereiice of the Danaoid Ili'licoi/idd', vvliilsl tlu-i]' near kindred are de- 

 ♦ .Mr. W'allncf tells me the Ei(p!a'tP of tlie Eastern .Vrcliiiielago have also this iieculiar smell. 



