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
Body in the cylinder that it had been part of a ventilation shaft. On 13 July 1945 three small boys were playing with the cylinder. They were rolling it through the streets when one tried to see what was inside. At first they saw what appeared to be a shoe, however, on closer inspection it appeared to be part of an human skeleton. The police were called to the scene and they used an Oxy acetylene burner to cut the cylinder open. The contents were revealed to be a complete human skeleton accompanied by a number of items. The police removed the remains and