20 
This affords us an excellent opportunity of learning 
effects of extreme temperature on some of our own 
common butterflies, which are also to be found in 
Japan, and if we select a few of these from the Japanese 
kinds mentioned we find first, that whilst the speci¬ 
mens which appear in March of the “ Swallow-tail 
Butterfly,” Papilio Machaon, are about 2J to 2f inches 
in the spread of the wings, and pale in colour, that the 
summer forms expand to about twice that extent, and 
are dark. 
The “Pale-clouded Yellow Butterfly,” Colias Hyale, 
is about If inch in expanse, whilst a large summer 
specimen will measure 2f inches; and the “ Small 
Cabbage White,” Pieris Rapce (which, it is noted, does 
not differ either in its larval or pupal state, or its 
food-plant from our own kind), is small and light- 
coloured when it appears in March, whilst the later 
broods are larger, and the female darkly coloured at 
the base of the wings. A circumstance is also noted 
with regard to this kind which points very strongly 
to these differences being the direct effect of tempera¬ 
ture, and not merely a periodic or seasonal difference 
in the state of the insect. Mr. Pryer mentions even 
in July he has taken, at an altitude of 8000 feet up 
Fujisan, smaller specimens than those taken in March 
near Yokohama, which is only about 100 feet above 
the sea. 
In the case of another kind, Papilio Maacki, of 
which the early form is usually small and bright, and 
the summer one larger and darker, Mr. Pryer secured 
both forms in one day in June, the large form being 
abundant at 2000 feet altitude, and the smaller or 
cold-temperature form being equally abundant 1500 feet 
higher yet up the mountains. 
I have quoted at some length from Mr. Pryer’s long 
and useful paper, because the subject is not only of 
practical interest, but also because, whilst so much is 
said, as at present, regarding alterations of species, 
it is of importance to see how temporary circumstances 
