Ixxxil 
Diptera that there would be great difficulty in compiling even an approximately 
complete list of the indigenous species of that Order. Entomologists throughout the 
United Kingdom were requested to collect Diptera, noting the times and localities, 
and to assist the Council in the preparation of the Catalogue. 
Papers read. 
The following papers were read:—“ Descriptions of New Species of Cryptoceride,” 
by Mr. Frederick Smith. The new species were eight in number, four of the genus 
Cryptocerus from South America, three of Meranoplus from West Australia, and one 
of Cataulacus from Borneo. 
“ On Species and Varieties,” by Captain Thomas Hutton, F.G.S. After referring 
to an assertion by Dr. Bree in ‘The Field’ newspaper, February 4, 1866, that the 
identity of the species Attacus Cynthia and A. Ricini “is proved by their breeding 
together, and by the produce after three or four generations having a tendency to 
return each to its separate type,’ an opinion in some measure endorsed by Dr. Wallace, 
who was “ inclined to agree with Dr. Bree that there is but one species, modified by 
climate, food, and domesticity,’ Captain Hutton continued as follows:— 
“That these opinions are erroneous will, 1 think, become apparent when we 
consider that Bombyx Huttoni, which cannot be domesticated, and the cultivated 
Bombyx Mori of China, two undoubtedly distinct species, will likewise breed together, 
and produce prolific eggs, as is the case with several other species, so that Dr. Bree’s 
opinion at once meets with a substantial refutation; besides that there being, as he 
says, a tendency to return each to its separate type, is a contradictory admission that 
the insects belong to distinct species, since if they belong to separate types they 
clearly do not belong to the same specific type. | Were they of the same species there 
would be no tendency to revert, because there would be nothing to revert to, and 
Attacus Ricini when uncrossed by A. Cynthia shows no tendency to revert to that 
species. The very fact of there being this tendency to revert shows that the species 
are distinct, and that the cross being contrary to the laws of Nature, an effort is being 
made by her to cast out the cross and return to the original and separate types. But 
if the mere fact of species breeding together is to be accepted as a proof of identity, 
then does Dr. Bree very satisfactorily prove that the horse and the ass are of the same 
species, and that the apparent degeneracy of the latter is, according to Dr. Wallace’s 
view, to be attributed to modification by climate, food, and domesticity. It may, how- 
ever, be objected in this case that the progeny are not prolific inter se, which greatly 
alters the case; nevertheless the progeny are prolific if crossed again either by the horse 
or the ass. I am, moreover, of opinion that the power of producing offspring is not due to 
the near affinity of species ; but is altogether dependent upon the fact that the parents, 
being of the same genus, must necessarily possess the very same structural model, 
without the least reference to or interference with specific characters. But if Attacus 
Cynthia and A. Ricini are to be regarded as one and the same species, modified by 
‘climate, food and domesticity, how comes it to pass that specific characters have been 
obliterated and others acquired? Diminished brilliancy of coloration might doubt- 
less be induced by climate, food, and other causes, but there would be no change of 
typical or specific characters, while colour, under an alteration of treatment, might 
easily be restored; but I would ask, if A. Ricini be only a modified variety of A. 
