( Ixxv ) 
small, when contrasted with the very large number of species 
of the groups to which they belong ascertained to inhabit 
the Region; but it may be observed that a considerable 
proportion of them must be of greatly extended occurrence 
and very ancient standing, Pryer* noting no fewer than six 
of them in Japan (besides three additional cases in local 
species); and Dr. A. Fritze + further recording in the same 
country the case of Araschnia levana (var. burejana),. 
When we turn tothe great tropical and subtropical Regions, 
where butterfly life finds its fullest and most varied develop- 
ment, it is almost disheartening to find how extremely little 
has been done in the observation of this apparently prominent 
feature of seasonal variation. With the exception of India 
in the Oriental Region, and South Africa in the Ethiopian 
Region, none of the hot or warmer countries have hitherto 
received the slightest investigation as regards this particular 
subject of biological inquiry. I can find no record of any 
observations in East or West Africa, in Australia, or in 
Central and South America. Feeling especially the deplore 
able lack of information from that paradise of butterflies, the 
Neotropical Region, I consulted Dr. F. A. Dixey with the 
view of ascertaiming whether the Pierinee—the group which he 
has made so emphatically his own, and which in the Old 
World has yielded more cases of seasonal dimorphism than 
any other—offered any instances of the kind in Central or 
South America. He most obligingly brought together, in 
the Hope Department of the Oxford University Museum, 
a series of Neotropical species of Callidryas, all of which 
included forms corresponding in character with the seasonal] 
varieties occurring among their Old-World congeners and 
allies, viz., a larger form, of deep or rich colouring with the 
underside freckling and markings strongly expressed; a 
smaller form, of paler colouring, with the underside freckling 
* “ Rhopalocera Nihonica: a Description of the Butterflies of Japan,” 
1886-88. The species named are Papilio machaon, P. xuthus, Pieris napi, 
Colias hyale, Vanessa C.-album, and Polyommatus phleas. 
+ Zool. Anzeiger, 1890, p. 12. Transl. in Ann, and Mag. Nat. Hist., 
6), v, p. 200 (1890). 
