Monarch Mystery Solved, and the Large White Somme

Since my startling encounter with a Monarch butterfly last week, I've discovered that there have been several sightings in the Home Counties. The explanation is that some enterprising company has started importing live Monarch to be released at weddings. Hmm. At least the sturdy Monarchs will stand a better chance than the frail Large Whites released en masse at the Rolling Stones' free concert in Hyde Park in 1969. I honestly can't remember if I was there or not (that's the Sixties for you). If I was, I was certainly mooching somewhere on the outer periphery, seeing nothing of the action and hearing only the distorted boom of distant rock. So I was spared that sorry business when Jagger read from Shelley's Adonais, in memory of the late Brian Jones - and the butterflies were released...
  The Stones - rock 'n' roll rebels that they were - were flouting Royal Park regulations, which insisted that any released butterflies should be sterilised (how?) and must on no account be of the species Pieris Brassica, the Large (or 'Cabbage') White. The Rolling Stones' people had acquired some 2,500 Large Whites, but by the time of the release all but a few hundred were dead from lack of air. The butterflies, noted Charlie Watts later, were 'a bit sad, there were casualties, it was like the Somme'. Most of those that managed to take to the air were soon flopping to the ground to die...
  These are the lines that Jagger read on that day:
'Peace, peace! he is not dead, he doth not sleep
He hath awakened from the dream of life
'Tis we, who lost in stormy visions, keep
With phantoms an unprofitable strife,
And in mad trance, strike with our spirit's knife
Invulnerable nothings. — We decay
Like corpses in a charnel; fear and grief
Convulse us and consume us day by day,
And cold hopes swarm like worms within our living clay.
The One remains, the many change and pass;
Heaven's light forever shines, Earth's shadows fly;
Life, like a dome of many-coloured glass,
Stains the white radiance of Eternity,
Until Death tramples it to fragments. — Die,
If thou wouldst be with that which thou dost seek!
Follow where all is fled!'
  In a rare moment of humility and sound judgment, Shelley wrote, after inviting the ailing Keats to stay with him at Pisa, 'I am aware indeed that I am nourishing a rival who will far surpass me and this is an additional motive & will be an added pleasure.' Indeed.