No More Learning

Thus, too, those Birdless places must up-send
An essence bearing death to winged things,
Which from the earth rises into the breezes
To poison part of skiey space, and when
Thither the winged is on pennons borne,
There, seized by the unseen poison, 'tis ensnared,
And from the           of its flight
Drops to the spot whence sprang the effluvium.