Page:The Zoologist, 1st series, vol 4 (1846).djvu/106

1272 wards the higher parts of the slope. And herein I imagine that I re- cognize a beautiful instance of natural instinct, both in the butterfly and caterpillar : the former deposits its eggs low down the declivity, where the young brood may rest most securely sheltered and least ex- posed to the wintry storms, but when the caterpillars are sufficiently advanced in growth, they ascend to the higher parts of the steep to feed and undergo their transformation : were the chrysalis formed below, they would probably have too much moisture and too little sun ; whereas by being formed higher up they have a sufficiency of both to bring them to maturity.

This butterfly is single-brooded ; but there is a succession of them, varying in duration according to the season. The earliest dates on which I have met with it is May 1st, the latest in July ; but in the latter case the specimens were bred in captivity. I never remember to have seen it so late in the state of liberty ; not later indeed than the middle of June here. They are very difficult to rear from the larvae, and those that I have bred, are not only disclosed much later than in the state of freedom, but are not nearly so fine and perfect. They in general fly slowly and peacefully, except when alarmed, gliding gently from flower to flower. I have taken as many as two dozen without moving from the spot where I stood, as they successively visited the stems of the grasses round me.

This Fritillary was much less plentiful last season than heretofore ; and in some of its former haunts has quite disappeared. It has many foes : for besides the march of improvement in cultivation which gra- dually invades its haunts, the same natural causes which promote its abundance, also multiply its enemies. Silpha obscura and tristis de- stroy the larvae : and a large ground spider, veiy numerous in the spots which it frequents, feeds on the perfect insect ; it lies in wait till the butterfly ahghts upon the low plants, or on the ground, then rushing forward, seizes it by the neck, and holds it captive with such tenacity, that both insects may almost be pulled in pieces, ere it will relax its grasp.

Migration of Butterflies.— By the assistance of friends and correspondents in dif- ferent parts of the island, we have been enabled to trace the course taken by the white and yellow butterflies in their annual migration. They were seen crossing the Kandian mountains all in the same direction, varying slightly from south-west, and simulta-