How many angels can dance on the head of a pin? dancing on a needle's point occurs in an expository work by the English divine, William Sclater (1575-1626). In "An exposition with notes vpon the first Epistle to the Thessalonians" (1619), Sclater claimed that scholastic philosophers occupied themselves with such pointless questions as whether angels "did occupie a place; and so, whether many might be in one place at one time; and how many might sit on a Needles point; and six hundred such like needlesse points." Harrison proposes that the reason an English writer first introduced the "needle’s point" into a critique of medieval angelology is that it makes for
Psittacine beak and feather disease and beak make tissues vulnerable to secondary infection. Because the virus also affects the thymus and Bursa of Fabricius, slowing lymphocyte production, immunosuppression occurs and the bird becomes more vulnerable to secondary infections. Beak fractures and necrosis of the hard palate can prevent the bird from eating. The ornithologist Edwin Ashby observed a flock of completely featherless red-rumped parrots ("Psephotus haematonotus") in the Adelaide Hills, South Australia, in 1888. The species then disappeared from the area for several years. The condition is more prevalent in widely occurring Australian species such as the sulphur-crested cockatoo, little corella and galah. The first