As everything connected with so strange a creature is very attractive, I will cite what other observers also have seen. Mr. Dale, from whom Curtis received _Elenchus_ to figure in his ‘British Entomology,’ vol. v. pl. 226, says: “These parasites look milk-white on the wing, with a jet-black body, and are totally unlike anything else. It flew with an undulating or vacillating motion amongst the young shoots of a quickset hedge, and I could not catch it until it settled upon one, when it ran up and down, its wings in motion, and making a considerable buzz or hum, as loud as a _Sesia_; it twisted about its rather long tail, and turned it up like a _Staphylinus_. I put it under a glass and placed it in the sun; it became quite furious in its confinement, and never ceased running about for two hours. The elytra or processes were kept in quick vibration, as well as the wings; it buzzed against the sides of the glass with its head touching it, and tumbling about on its back. By putting two bees (_Andrena labialis_) under a glass in the sun, two _Stylops_ were produced: the bees seemed uneasy, and went up towards them, but evidently with caution, as if to fight; and moving their antennæ towards them, retreated. I once thought the bee attempted to seize it; but the oddest thing was to see the _Stylops_ get on the body of the bee and ride about, the latter using every effort to throw his rider. “As the _Stylops_ emerges from the body of the bee, the latter seems to suffer from much irritating excitement.” Mr. Thwaites writes to me, on the 12th May, thus: “I had the good fortune to capture a _Stylops_ flying, and on the Tuesday following saw at least twenty flying about in the garden, but so high from the ground that I could capture only about half-a-dozen; since that time they have become gradually more scarce. “The little animals are exceedingly graceful in their flight, taking long sweeps as if carried along by a gentle breeze, and occasionally hovering at a few inches distance from the ground. Their expanse of wing and mode of flight give them a very different appearance to any other insect on the wing. When captured they are exceedingly active, running up and down the sides of the bottle in which they are confined, moving their wings and antennæ very rapidly. Their term of life seems to be very short, none of those I have captured living beyond five hours, and one I extracted from a bee in the afternoon was dead the next morning. “All the bees stylopized, both male and female, I have taken, have manifested it by having underneath the fourth (invariably) upper segment of the abdomen a protuberance which is scale-like when the _Stylops_ is in the larva state; but which is much larger and more rounded when the _Stylops_ is ready to emerge. A bee gives nourishment generally to but one _Stylops_; but I have occasionally found two, and once three larvæ in one bee.”