Trachea Diffusion of oxygen and carbon dioxide takes place across the walls of the smallest tubes, called tracheoles, which penetrate tissues and even indent individual cells. Gas may be conducted through the respiratory system by means of active ventilation or passive diffusion. Unlike vertebrates, insects do not generally carry oxygen in their haemolymph. This is one of the factors that may limit their size. A tracheal tube may contain ridge-like circumferential rings of taenidia in various geometries such as loops or helices. Taenidia provide strength and flexibility to the trachea. In the head, thorax, or abdomen, tracheae may also be connected
The World Is What It Is The World Is What It Is The World Is What It Is: The Authorized Biography of V. S. Naipaul is a biography of the Nobel Prize-winning author V. S. Naipaul by Patrick French. It was published in 2008 (by Picador in the UK and Knopf in the USA). The title is a quotation from Naipaul's book "A Bend in the River". "The world is what it is; men who are nothing, who allow themselves to become nothing, have no place in it." French deals with Naipaul's family background and his life from his birth in 1932 until his second marriage