264 [April, 
Mr. E. Saunders exhibited various Bwpfestidm which he had compared with 
the Fabrician types in the Banksian collection, and also those species that had been 
considered by authors as identical with those of Fabricius, according to the descrip- 
tions J in many cases there were considerable discrepancies between these latter 
and the actual types. 
Mr. Dunning announced the death of Mr. Wilson Armistead, of Leeds, who had 
been engaged on a work on galls. 
LiNNEAN Society, March 5th, 1868 ; G. Bentham, Esq., F.R.S., President, in 
the Chair. — A paper " On some remarkable Mimetic Analogies among African 
Butterflies " was read by Mr. Roland Trimen. The author, after some remarks on 
the length of time during which instances of extraordinarily close resemblance 
between butterflies of wholly different structure had been allowed to pass without 
any attempt at explanation of their meaning, referred to Mr. Bates's well-known 
treatise " On the Heliconidce of the Amazons Valley " as containing the only rea- 
sonable elucidation of these remarkable phenomena that has been offered up to the 
present time. He also alluded to the fact that a similar series of phenomena in 
India and the Malayan Archipelago had been recorded by Mr. Wallace, who accounted 
for them on the same theory as that advanced by Mr. Bates. Some general 
remarks followed, showing that the conditions under which the cases of mimicry 
occurred in Africa were quite similar to those recorded with respect to the two 
other warm regions of the earth ; and the personal observations of the author in 
Southern Africa were adduced in support of the statement that the butterflies that 
are the objects of mimicry (the Danaidce and Acrceido}) were protected races, and in 
great measure exempt from persecution by birds and other devourers of insects. 
Eleven of the more striking instances of imitation were tabulated and described in 
detail by Mr. Trimen ; the most remarkable of which is perhaps the case of Papilio 
Merope, a butterfly that, according to the author's belief, presents in Africa four 
forms of female (all very widely diflfering from the male), three of which are 
manifest mimickers of three prevalent species of Danais ; while in Madagascar 
a local race of the same Papilio occurs in which the female differs but slightly from 
the male. 
The results of an examination of the conditions under which the cases of 
mimicry occurred were then briefly enumerated, as tending in every respect to 
confirm Mr. Bates's view that such imitations are brought about by natural 
selection, i.e., by the perpetual preservation of individuals possessing any protective 
variation of colouring and outline approximating them in aspect to the defended 
BanaidoR or Acrceidce, and the destruction of all those not favoured in like manner, 
and by the gradual development of the advantageous characters by inheritance 
during numerous generations. 
The paper concluded with the expression of the author's conviction of the 
harmonious relation existing between the theory of the mutability and gradual 
origin of species and what is now universally admitted as regards inorganic matter, 
viz., that geological changes, however profound, are the result of the gradual 
operation of the forces and agencies still at work under our eyes, and not of vast 
convulsions of nature or general cataclysms. 
