158 Mr. C. B. Williams' Notes on 



were noticed whenever the sun was shining; between 

 11.35 and 11.40 thirty-four passed over on a hundred yards 

 line. At 1 p.m. two or three per minute were flying rapidly 

 at the foot of the hill, all going south-east. At 2 p.m. they 

 were still passing, but none were seen after three o'clock. 

 One caught to-day was a male. 



bth August. — Very wet, 1*38 inches of rain ; no butterflies 

 seen. 



6th August. — They were first noticed to-day at 11 a.m.; 

 from 11.30-11.35 sixty-three passed over the garden, i. e. 

 thirteen per minute on a hundred yards line. 



7th August. — The butterflies are still migrating. At 

 9.30 a.m. six or seven per minute were passing the house ; 

 at 10.15 a.m. eight a minute were passing on a hundred 

 yards of garden ; and again at mid-day and at one o'clock 

 they were still flying. One specimen captured to-day was 

 a male. 



8th August. — At 11.15 a.m. they were again noticed 

 migrating. The sun seems to make a great difference to 

 the flight. I started counting at 11.16 a.m., and in the 

 first minute eight passed; then the sun went in, and in the 

 next four minutes only three were seen; in the first two 

 minutes of sunshine after this fifteen passed. Do they 

 follow the patches of sunhght, or settle when a shadow 

 comes ? The former does not seem possible, as they have 

 always been flying across the direction of the wind. At 

 1.15 occasional specimens were seen crossing the river, 

 but they were far apart; at a casual glance it might not 

 be noticed, but every ten seconds or so one would come 

 into view going full speed south-east. 



9th August. — The butterflies were still in migration, 

 but only occasionally in intervals between heavy showers. 



10^/i August. — The butterflies were plentiful to-day, 

 crossing the river at Issororo at least twenty to thirty per 

 minute on two hundred yards line. Half a mile between 

 Issororo they thinned out and remained at three or four 

 per minute right down to the river jimction; below this 

 to Morawhanna only very few were seen. I made an 

 attempt to-day to estimate the speed at which they were 

 flying; previously I had found it impossible to overtake 

 them even when on a clear footpath, and had considered 

 their speed as at the very least nine miles per hour. The 

 river now gave a good opportunity of testing this, as they 

 were passing directly across it and could be timed from 



