Even those visitors to Switzerland who do not claim to be naturalists have heard of the remarkably handsome and stately Butterfly known as Apollo. To the ardent entomologist, the first sight of this typical Alpine species is a never-to-be-forgotten delight, and he generally brings home with him a rich harvest of specimens. The more experienced Butterfly hunter knows that there are no less than three different kinds of Apollo--or, as we should say more correctly, of Parnassius--in Switzerland. There is first the common Apollo (_Parnassius Apollo_), then the rarer and more local _P. delius_, which inhabits more elevated regions, and finally the still scarcer _P. mnemosyne_, which is only known from the highest mountain ranges. It may be a surprise to those who have accustomed themselves to connect Apollo with the Alps, and who think the two belong together and cannot do without one another, to hear that it is by no means confined to them. It is also found in Scandinavia, France, Spain, Russia, and in Siberia. _Parnassius delius_ is confined to the European Alps and the mountains of Central Asia, while _P. mnemosyne_ is known from the Pyrenees, Sweden, Hungary, Sicily, Russia, and Western Asia. One other Parnassius inhabits Europe, viz., _P. Nordmanni_ of the Caucasus, but all the remaining species of the genus--and there are nearly thirty more--are confined to Central Asia. A few, as we have seen, have reached Europe, some have travelled to the Himalayan Mountains, and others to Western North America. The centre of distribution is certainly in Central Asia, and we have no reason to suppose that the original home in this case does not agree with that centre. _Melitæa_, a genus to which some of our British Fritillaries belong, has also some typically Alpine members. Two of these, viz. _M. cynthia_ and _M. asteria_, are peculiar to the Alps, the latter being only found at considerable elevations. Most of the remaining fourteen European species are also found in Central Asia. Thus the isolated _M. maturna_, which in Europe is confined to Lapland, is also known from the Altaï Mountains, which again are near the centre of distribution, since some species of _Melitæa_ range across the Northern Pacific to Western North America.