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 Secretary Liam Fox announced that General Sir David Richards, the then Chief of the General Staff, would succeed Stirrup as Chief of the Defence Staff in October 2010. Richards took over on 29 October 2010 and Stirrup was created a life peer as Baron Stirrup, of Marylebone in the City of Westminster. He was introduced into the House of Lords on 1 February 2011, where he sits as a crossbencher. Stirrup officially retired from the RAF on 4 April 2011. The following month Stirrup gave detailed evidence to the Commons Defence Select Committee on the UK's recent Strategic Defence and