lil 
Mr. W. W. Saunders exhibited a box full of Heliconie, “all taken together in the 
same locality” at Cayenne, including forms which have been described unéer seven 
or eight specific names; the examination of these specimens had convinced him that 
all of them were referable to a single species, H. Melpomene, or at most to two 
species; the structure and general form were constant, whilst the colour varied 
enormously, so that if his conclusion were correct colour must henceforth be con- 
sidered as of small specific value amongst butterflies. 
Mr. Bates said that he had found nearly the whole of the same forms on the 
Amazous, and had come to the conclusion that there were three species, Heliconia 
Melpomene, H. Thelxiope, and H. Vesta, but that the majority were merely inter- 
mediate varieties. , In their typical states those three were perfectly distinct, did not 
' interbreed, and no connecting links were found. For a distance of 1800 miles up the 
Amazons, Heliconiew occurred everywhere, but the intermediate varieties were found 
in only one locality, on the hilly maivland of or adjoining Guyana, at the other 
extremity of which was Cayenne. The three species occurred in the forests, but the 
varieties did not. He had endeavoured to investigate the question whether the species 
interbred, and whether the varities were the result, and had satisfied himself that the 
varieties were not hybrids. He thought that the insects were unstable vacillating 
‘ species; H. Melpomene, Thelxiope, and Vesta had become segregated in the alluvial 
plains, and might now be considered as species, though in bis opinion they themselves 
were the descendants of some one prior unstable form which was their common 
ancestor. He conceived that the whole phenomena, both of the formation or develop- 
ment of the different species and the existence of the intermediate varieties, were 
explicable on the broad principle that an insect, in disseminating itself over a wide 
area, adjusts or accommodates itself to local conditions. 
Mr. Saunders remarked that the Heliconie exhibited were all from the same 
locality, and therefore presumably had been subjected to like conditions. 
Mr. Bates admitted that many different varieties were found in one spot; but as 
local variation was not the only form of variation, such collocated varieties might be 
produced by causes similar to those which produced the remarkable beg between 
the offspring of some of our domestic animals. 
Dr. Alex. Wallace said that the course which the discussion had taken led him to 
enquire whether Bombyx Ricini and Bombyx Cynthia were distinct species ; the two 
insecis interbred, and the hybrids were fertile and bred on for generations, not only 
amongst themselves, but with either of the parent furms,. And yet B. Ricini was from 
Bengal and fed on Ricinus communis; B. Cynthia from China and fed on Ailanthus 
glandulosa; they differed in the egg, in the colour of the larve, iv the shape of the 
cocoon, in the quality of the silk, in the imago, and in their habits. B. Ricini 
produced six or’ seven generations in the year, aud was tvo fertile for this country, 
since it could not be prevented from hatching in winter when no food for the 
larve was obtainable; whilst B. Cynthia, though last year it had produced four 
generations in France, in an ordinary season produced only two, and perhaps a single 
generation would be the rule in this climate. 
Mr. J. J. Weir enquired on which plant the hybrids fed ? Dr. Wallace replied, on 
both or either indifferently. 
Mr. F. Smith said that the remarks he had made at a previous Meeting, (see 
‘Proceedings,’ 1865, p. 130), as to the tapping noise alieged to be made by “ death- 
