Brain size area in women, corresponding to spatial versus language specializations. Small studies have attempted to link brain volume with functional measures such as P300 auditory evoked potentials but finding no association. Studies attempting to related sibling differences in IQ to differences in brain volume are hampered by relatively small sample sizes and the noisy nature of such difference scores, yielding weak evidence for cross-trait cross-sib correlations. The largest brain is that of the sperm whale, weighing about , and killer whales, weighing about . An elephant's brain weighs just over and a bottlenose dolphin's . Brain size tends to vary according
The Brain of Morbius the ruins. Morbius attacks the Doctor, but is knocked out by Solon's tranquilliser. As they carry the creature back to the castle, the Doctor tells Solon that Morbius's brain will be detached and returned to the Time Lords. The body of the dead Sister is brought back to Maren. Ohica reports that witnesses saw a creature and then the Doctor and Solon hunting for it. Maren realises that Solon has succeeded in his experiments and resurrected their ancient enemy. But Maren is too old and weak to leave the shrine, and she gives Ohica permission to lead the Sisters to