is shown on a stretcher following the parallel events of "The Runaway Bride". A UNIT officer states that the Doctor's death must have been too quick to allow for regeneration. In Destiny of the Daleks, Romana showed the ability to rapidly change form several times in a row during her first regeneration, and apparently had the ability to change into whatever appearance she desired. When the Doctor remarks upon her ability, she comments that he should have stayed in university. However, despite showing several appearances, Romana regenerated only once on that occasion. In "Utopia", the Master, just before regeneration, claimed that he would become "young and strong", implying that he could choose the form of his new body. The human-Time Lord hybrid River Song in "Let's Kill Hitler" claimed she was "focusing on a dress size", but subsequently weighed herself, seeming unsure of how her new body had truly developed. The Doctor said on several occasions he wished he was "ginger", which he has seemed unable to control in previous regenerations. In "Last of the Time Lords", when the Master is fatally wounded, he chooses not to regenerate, essentially committing suicide rather than regenerate and be kept prisoner by the Doctor forever. This again implies that regeneration is not inevitable and can indeed be refused. Upon encountering the remains of fellow Time Lord the Corsair in "The Doctor's Wife", the Doctor refers to the Corsair as both male and female, hinting that Time Lords can switch genders upon their regenerations; this is confirmed in "Dark Water", in which the Master, previously seen in various male incarnations for over forty years, returned as a female. The Thirteenth Doctor also regenerated as a woman in "The Woman Who Fell to Earth". Whether or not Time Lords can recognise each other across regenerations is not made entirely clear: In The War Games, the War Chief recognises the Second Doctor despite his regeneration and it is stated that they know each other when they first meet. In Terror of the Autons, the Third Doctor fails to recognise The Master's voice, when the Master speaks to him on a telephone. In The Three Doctors, the Second Doctor recognises the Third Doctor immediately, despite the fact that the Third Doctor is a future incarnation of himself. Omega is similarly able to recognise the two Doctors as the same man. In Planet of the Spiders, the Third