534 
BIONOMIC NOTES 
existence, if the mimetic guise often, or even occasionally, leads to 
the escape of the protected species, it must be a great advantage to 
it. The same argument applies to distasteful qualities. 
The question to be decided is not, “ Is the disguise always suc¬ 
cessful in deceiving all enemies ? ” but rather “ Does it ever deceive 
any enemies ? ” 
§ 7. Notes on the Flight of Sundry Butterflies. 
Too many systematic works deal with insects as mere cabinet 
specimens, though there are notable exceptions. Not the least 
valuable part of the late Mr. C. G. Barrett’s great work on the 
“ Lepidoptera of the British Islands ” is his vivid description of their 
habits and flight. Again in Moore’s “ Lepidoptera of Ceylon ” the 
short notes on the mode of flight of many species supplied by Capt. 
H. Wade-Dalton, Mr. F. M. Mackwood and more frequently Capt. 
F. S. Hutchison are of great interest. The value of the notes in the 
last-named work is not diminished by the fact that the observers are 
not always agreed. The habits of the sexes are usually different; 
the time of day, not to speak of the weather, greatly affects their 
flight; probably the time that may have elapsed since emergence 
from the pupa is another important factor. From these facts it 
follows that hasty generalizations based on even the most accurately 
recorded observations may be misleading if the qualifying circum¬ 
stances be left out of account. 
The first fact that I would emphasize is the rapid flight of the 
Whites and Yellows . 1 That Pierines may be seen fluttering about 
flowers is true enough, e.g. Colias edusa is not always difficult to 
catch. Nevertheless the Pierine has a knack of flying straight ahead 
in a business-like manner, as if bound to reach some distant place 
at a definite time, in a way that the Satyrine rarely, if ever, adopts. 
Again, though the Nymphaline may go off at a great pace for a 
short distance, it usually soon returns to its beat. Among many 
swiftly flying Pierines that I have come across, are:—-the allied 
genera Gatopsilia, 2 Callidryas 3 and Gonepteryx ; Gatophaga paulina; 
the Neotropical Glutophrissa drusilla, and more especially Pieris 
phileta ; 4 the powerful Oriental Hebomoia ; 5 again Ixias pyrene 
1 See above, pp. 44, 58, 98. 2 See above, p. 58. 
3 See above, pp, 286, 331. 4 See above, p. 287. 
5 See above, pp. 102, 114, and subsequent experience in Ceylon. 
