Mr. Kirby, in studying the bees for his invaluable ‘Monographia Apum Angliæ,’ first came across this extraordinary creature. His description of his discovery is highly interesting. He says, at page 111 of volume ii. of the above work, that having observed a protuberance upon the body of the bee, he was anxious to ascertain whether it might be an _Acarus_, and goes on: “What was my astonishment when, upon attempting to disengage it with a pin, I drew forth from the body of the bee, a white fleshy larva, a quarter of an inch long, the head of which I had mistaken for an _Acarus_. How this animal receives its nutriment seems a mystery. Upon examining the head under a strong magnifier, I could not discover any mouth or proboscis with which it might perforate the corneous covering of the abdomen, and so support itself by suction; on the under side of the head, at its junction with the body there was a concavity, but I could observe nothing in this but a uniform unbroken surface. As the body of the animal is inserted in the body of the bee, does that part receive its nutriment from it by absorption? After I had examined one specimen, I attempted to extract a second, and the reader may imagine how greatly my astonishment was increased, when, after I had drawn it out but a little way, I saw its skin burst, and a head as black as ink, with large staring eyes, and antennæ consisting of two branches, break forth, and move itself briskly from side to side. It looked like a little imp of darkness just emerging from the infernal regions. I was impatient to become better acquainted with so singular a creature. When it was completely disengaged, and I had secured it from making its escape, I set myself to examine it as carefully as possible; and I found, after a careful inquiry, that I had not only got a nondescript, but also an insect of a new genus whose very class seemed dubious.”