She heard her father's voice as she prepared, remembering all the times she had taken dictation for him, or had overheard him instructing young botanists. 'Be wakeful and watchful,' she heard Henry say. 'Make sure you are not the only member of your party who can write or read a letter. If you need need to find water, follow a dog. If you are starving, eat insects before you waste your energy on hunting. Anything that a bird can eat, you can eat. Your biggest dangers are not snakes, lions, or cannibals; your biggest dangers are blistered feet, carelessness, and fatigue. Be certain to write your diaries and maps legibly; if you die, your notes may be of use to a future explorer. In an emergency, you can always write in blood.