viii 
PEEFACE. 
The series of variable species retained in most collections are much too 
short. — among the varieties the specimens most distinct from the typical 
form being, as a rule, the only ones preserved, the more interesting, and 
often much rarer, intermediate forms or links being discarded. As a rule, a 
named variety or a local form is not constant, and a form occurring in one 
country as an occasional variety may be the dominant form in another country : 
e. g. Colias edusa, var. helice, is much more plentiful in the Canary Isles than 
the typical female ; and in China the var. valezina of Argynnis paphia is the 
common form of female, while in Japan an intermediate form of this sex 
alone is met with. The importance of long series of variable species, with 
correct data, from different localities cannot be over-estimated, and the absence 
of such series for comparison has no doubt led to the naming of so many bad 
species. 
Field-work appeals to most entomologists as a recreation, or, it might 
almost be said, as a form of sport. It affords the busy professional or 
commercial man an opportunity of enjoying an interesting and exciting 
pursuit amidst attractive natural surroundings. To sportsmen of leisure, 
among whom are many entomologists, it offers an occasion for profitably 
employing the interval between the hunting- and shooting-seasons. 
Many Lepidoptera are exceedingly difficult to capture, and to obtain them 
great perseverance and dexterity are requisite. The most sporting butterfly 
known to the author is Parnassius charltonius. His first acquaintance with 
this species was in 1887 on the Skoro-la Pass, amongst the glaciers of Baltistan 
ill tlioN.W. Himalayas, at an altitude of about 18,000 feet. At that time 
il.c species was very rare in collections, and on first observing it the Author 
an.l Mr. dc Niceville, who accompanied him, determined at once to procure a 
gr,o(l series at any price. The ground was very badly adapted for forming a 
cump, l)ut aClcr a little searching a more or less level spot was found on 
wliich tlic coolies were set to work digging away the mountain side, and by 
