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
Where the Sidewalk Ends (poem) the children because they know the place where the sidewalk ends. Looking more in depth at this poem makes clear what Shel Silverstein is saying. Do what the children do. They know the place where the sidewalk ends. And in doing so, you will find the joy and passion for life that they have. When he says to follow the markings of the children and you will find the place where the sidewalk ends, it is not a literal command to physically follow them. Rather he is saying put on the mindset of a child and you will, in turn,