Evolution of the cochlea about 7 mm long. Like in lepidosaurs and archosaurs, it contains a lagena, a vestibular sensory epithelium, at its tip. Only in therian mammals (marsupials and placentals) is the cochlea truly coiled 1.5 to 3.5 times. Whereas in monotremes there are many rows of both inner and outer hair cells in the organ of Corti, in therian (marsupial and placental) mammals the number of inner hair-cell rows is one, and there are generally only three rows of outer hair cells. Amphibians have unique inner ear structures. There are two sensory papillae involved in hearing, the basilar (higher frequency) and amphibian
Jock Stirrup Staff in 2006: during his time in office the British Armed Forces faced significant commitments both to Iraq (Operation Telic) and Afghanistan (Operation Herrick). Stirrup retired as Chief of the Defence Staff on 29 October 2010, taking a seat in the House of Lords in 2011. Graham Eric Stirrup was born on 4 December 1949, the son of William Hamilton Stirrup and his wife, Jacqueline Brenda Stirrup ("née" Coulson). He was educated at Merchant Taylors' School in Northwood, Hertfordshire. Stirrup married Mary Alexandra Elliott in 1976 and they have one son. Stirrup includes golf, music, theatre and history among his