viii PEEFACE. 
The scries 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 maybe the dominant form in another country : 
e. g. Colias ednsa, var. Iieh'ce, 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 Avhom are many entomologists, it offers an occasion for profitably 
employing the interval between the hunting- and shooting-seasons. 
Many Lepidoptera are exceedingly difficult to captiure, and to obtain them 
great perseverance and dexterity are requisite. The most sporting butterfly 
known to the author is Parnassms charltoiiius. His first acqaaintance Avith 
this species was in 1887 on the Skoro-la Pass, amongst the glaciers of Baltistan 
in theN.W. Himalayas, at an altitude of about 18,000 feet. At that time 
the species was very rare in collections, and on first observing it the Author 
and Mr. de Niceville, who accompanied him, determined at once to procure a 
good series at any price. The ground was very badly adapted for forming a 
camp, but after a little searching a more or less level spot was found on 
which the coolies were set to work digging away the mountain side, and by 
