As regards the scab, itch, and mange insects or mites (acarid), three perfectly distinct forms are known.
Many insects are always covered with certain species of acarid.
They have always perplexed entomologists, who seem to consider them as parasites allied to acarid and lice.
Leroy de Mricourt found in pus, which was running from the ear of a sailor, acarid which Mons.
acarid ac·a·rid (āk'ə-rĭd)
An arachnid of the order Acarina.