The Birmingham age-herald., 1911-09-24
A MYSTERY OF MIGRATION
For Years Horde of Butterflies Light
 on Same Limb in Flight South

From the St. Paul Dispatch
 once again on their annual pilgrimage
 which never has failed in the last ten years, thousands of beautiful monarch butterflies, all the same color and all 1he same species swarmed on the limps oi trees in the yard in the rear or the nome of Mrs. w. D. George, Dayton avenue
 yesterday afternoon. hanging In great clusters so thick in places the .rees seemed spotted with brown.
 About o'clock they began to come, hundreds in a flock, flying as straight as II guided by an unseen hand. Past hosts ol other trees they flew unhesltatlngly, ma
 with an unerring instinct sought resting places on the limbs of the very trees tha, has been the temporary shelterlng or tnon- sands of their ancestors in years gone py. More singular was the quest of the put terfies of former years that had sought out this resting place over night on their journey south. Nine years in succession so long has Mrs. George kept account they came to one particular long limb Of a, box elder In the yard, literally concealing it with their clusters.
 Other limbs on that tree were ignored, as the butterflies yesterday ignored other trees in adjoining lots. This was -helr resting place for the night-no other
 would do Unerringly they found H.
 hanging low to the ground. and never did
 they leave it until sunrise
 Last year this limb was cut off, so When the butterflies returned this year the oid
 place of vantage was gone and they rlds-
 tered on the outer branches Of this ana
 other trees in the yard But in the one yard they stayed, loyal though the old home was gone.
 What guides them to one spot in St Paul is a scientific mystery made more involved because it is aid butterflies live only one year, hence none from last wear could have guided them this season to the trees Mrs. George, who has watched them for years and has seen thousands come and thousands go, offers no eXplana- ton for the ever recurring visit
 This butterfly is known commonly as the lnilkweed butterfly" said A. c. Rug gles, assistant professor in the division of entomology of the State Agricultural school. when consulted last night. ''The scientific name is Anosia plexippus, and 1t belongs to the family Lymnadidas It de- riyes it's common name because the cater pillar from which 1t comes feeds almost entirely on milkweed.
 "TEese butterflies are nauseous to birds and hence are able to congregate as they do with impunity. They have a northern migration in the spring and southern in the fall, different from that of birds in this way, that the female butterflies come north about the time the milkweed begins to grow in the spring, lay their eggs and die soon after. Matching from these eggs are the caterpillars that feed on the weed eventually changing into buttern'es which fly still further north, where che female again lays eggs.
 And so generation after generation IS produced the adults migrating further and further north, until we find them late in the season often as far north as l1ud- sons bay In the fall they gather in great fiocks and fly south.
 They are great fiiers and we know they can cover 5oa miles at least, because speei- mems have been taken on the ocean that distance from shore. The monarch is a native of America, but Is now practically cosmopolitan, being fonnd almost every where on the globe