BUTTERFLY MIGRANTS

Evening Post, Volume CX, Issue 34, 8 August 1925, Page 16

BUTTERFLY MIGRANTS

■NATURE'S BOOK OF RIDDLES.

I If the migration of the birds be ac- ! counted a marvel, then the trek of the | butterflies must be admitted to be a miracl*. They seem too delicate for sustained flight, and fit only to be the fairies' messengers. And yet the beautiful "painted ladies" winter in Central Africa, south of the Sahara, and make a summer journey which takes a few , pioneers right away into Iceland. This long journey is begun in the early : spring, and the hardiest reach their ' northern limits some time in July. In April they reach the southern shores of ■ the Mediterranean, and then comes the great divide, writes G. F. M. Cox, in I the "Daily Chronicle.'' The one band moves in great fluttering clouds of colour northward along the

! overland route, through Palestine and by way of Syria, and Turkey into the Balkan States; the others cross the Mediterranean into Southern Europe, reaching there early in May, and, leaving strugglers behind all the way, cross .the Channel into England by the end of the month. The constantly depleted mass pushes ori- ■ ward into' Scotland, and the hardiest I finish their . trek" across half a hernia-

phere in Iceland, from which Ultima Thule they never return. But what is perhaps more wonderful still is that a southward journey has i never been observed. Those which come 1 here to England lay their eggs, which hatch out into caterpillars, and these become butterflies which perish in the land of their birth. If stragglers do return they have never been seen, and if they move in battalions their flight must take place at night. The riddle of the birds' summer flight has not yet been solved. ' The swallow which winters in Natal and nests in England traverses a, route, that ho has travelled before. He has taken a return ticket, but the "painted ladies" know naught of such things. They come here, breed, and die here, and.. their progeny never leave our shores. The mystery of this migration defies solution, and the latest theory .advanced serves only to deepen the mystery. Mr. i'C. B. Williams/the chief entomologist of the Egyptian Ministry of Agriculture, suggests that it is hardly a migration I within the meaning of the act, but a sort of gigantic living aerial race. He puts forward the theory that those who begin the trek are not the one* that finish it, but that one .batch flies so far, deposits its eggs, and then the progeny continues the journey. If his theory be true, then we are faced with a problem even more inscrutable, beside which the riddle of the Sphinx is an open book, Nature, as all her lovers know, is a gigantic book of riddles. The early naturalist made wild guesses, his successors have found some solutions, but the riddle of the "painted ladies" migration seems able to defy the most patient and persistent searchers for all time