572 The Zoologist — February, 18G7. 



2. Between different classes of the same kingdom : Ex. Humming-bird and 



humming-bird moth; eel and snake. 



3. Between different orders of the same class: Ex. Vespa and Ceria; Trochilium 



and Vespa; Eristalis and Apis; Tricondyla and Condylodera. 



4. Between different sections of an order: Ex. Papilio and Urapteryx; Carabus 



and Adelinm. 



5. Between different families of a section : Ex. Papilio paradoxus and Danais; 



Leptalis and Heliconia. 



6. Between different genera of a family: Ex. Species of various genera of 



Heliconiida\ 



From the latter instances, the Professor thought it was evident that the relation 

 which had been termed mimetic resemblance was only an exaggerated analogy; and 

 as these analogies (more or less complete) were found to occur throughout nature it 

 might be assumed that they formed an element in creation, and hence that it would be 

 unphilosophical anil illogical to refer their occurrence in a more striking degree, in any 

 one instance to a special cause, although the analogy did certainly in many cases 

 seem to be gnen to the creature for pui poses of protection. In the MacLeayian and 

 Swainsouian systems these analogies were considered as existing as tests of affinities, 

 and without regarding or employing them in the sense adopted by the authors of those 

 systems, it seemed to Prof. Westwood that it was necessary to take them into con- 

 sideration in endeavouring to arrive at a correct view of the general '' System of 

 Nature." Applying the preceding observations to the mimicry exhibited by the various 

 Pierida? (chiefly of the genus Leptalis) of different species of Heliconiida? described by 

 Mr. Bates, Prof. Westwood contended that Mr. Bates's supposition that the imitation 

 had been assumed by the former in order to enable them to subsist (the Heliconiida; 

 which possess a strong and disagreeable odour being found to be dominant in South 

 America) was not tenable — 



1. Because the mimicking species could barely be said to exist, much less to 



flourish, in the country where the Heliconiida; abounded," not oue iu a thousand'' 

 having been found by Mr. Bates. 



2. Because there still occurred numerous species of white Pierida? in the country 



of the Heliconiida? in a nourishing condition. 



3. Because there were vast numbers of other groups and species of butterflies in 



Brazil equally subject to attacks of birds with the Pieridae, which had never 

 attempted the assumption of forms of the dominant group, Heliconiida?. 



4. Because there were great numbers of instances of mimicry between the different 



Heliconiidae themselves, which could not have the inducement to mimicry 

 attiibiited to the Pieiids. 



5. Because there were species of Pieridce (such as that to which Mr. Hewitson's 



mustious individual belonged) of which only one sex mimicked the Heliconiida?. 

 It would require a wide stretch of imagination to suppose that natural selection 

 could have led to the assumption of such mimicry by the individuals of only oue 

 of the sexes of a species.* 



* Papilio /Enea exhibts a double system of mimicry, the male resembling Danais 

 Echeria and the female Danais Cbr^sippus! 



