THE PHYSIOLOGY OF SLEEP.! 
By R. LEGENDRE. 
Sleep is one of the most necessary functions in our lives. It oecu- 
pies a third of our existence. It is therefore not at ail strange that it 
should be a subject of deep study and research by numerous inyesti- 
gators; in fact, poets, philosophers, psychologists, physicians, physiol- 
ogists, and others contemplate the subject and examine it from their 
several points of view. 
To poets, according to their feeling at the moment, sleep is in turn 
distasteful or pleasing. Wishing for action, they call it ‘‘brother of 
death,’”’ but more frequently, absorbed in reveries and dreams, they 
banish that thought, for sleep no more resembles death than does a 
smoothly flowing stream resemble the calm surface of a lake. 
Day is for evil doing, for weariness, and hate. 
Night is the well-beloved, she who brings tranquillity, repose, and 
dreams; and the poets invoke her, begging her to stay. 
Oh, venerable night, from whose depths profound 
Through endless space peacefully flow 
Broad silvery streams from countless worlds, 
And into man pours calm divine. 
* * * * * 
All life is mute, for neath thy spreading wing 
It drinks of sleep at shade of eve, 
A milk deep and wondrous, that 
All lips imbibe in silence at thy dark breast. 
Sutity PrupHOMME. 
Sleep seems even as a god who, with forehead crowned with poppies 
and wrapped in dreams, slumbers in the depths of an obscure grotto, 
isolated by the river of forgetfulness. 
To philosophers, also, sleep is a subject of deep thought. It opens 
up, indeed, two great problems: First, one may ask what becomes of 
our consciousness during sleep, and the question is an important one 
when we agree with Descartes that thinking is proof of our existence. 
Should we believe that the mind acts continuously in our dreams ¢ 
Males fr tiveceglt viel Seeety eet oe eon ee te 
1 Lecture delivered May 7, 1911, at the National Museum of Natural History, Paris. Translated by 
permission from Revue Scientifique, Paris, forty-ninth year, Tune 17, 1911. pt 
