ANIMAL SLEEP n 



not seem possible for them to awaken. Light be- 

 numbs their faculties like freezing cold, and they 

 seek darkness with the same instinct that a human 

 being, with senses benumbed by sickness, demands 

 more light. Bats, the only purely nocturnal animals 

 in this country, show this characteristic in its com- 

 pletest form. Their daylight sleep paralyses them, 

 though not because they are unable to see and fly 

 with safety in the sunlight, for they can do both. 

 But if handled and disturbed, they make no effort 

 even to spread their wings, and seem unable to shake 

 off the drowsy influence. Not even the great night- 

 flying moths are so completely the slaves of this un- 

 yielding habit of diurnal sleep. Contrasted with this 

 deep repose, the slumber of the great body of herbiv- 

 orous animals is so light and broken that it may be 

 doubted whether their senses are ever so completely 

 at rest as to deserve the name of sleep at all. In 

 human sleep the sense of hearing is that which re- 

 mains awake longest, and to which the brain most 

 readily responds. But in sound and heavy sleep, 

 the ear often suggests a long train of thought in 

 dreams before the brain awakens to a sense of reality. 

 In most sleeping animals, its warning is instantaneous, 

 and the faculties obey the call for action with no 

 apparent interval of inertia. A sleeping fox will rise, 

 gallop off, and dodge the hounds with as much cool- 



