158 THE BOOK OF A NATURALIST 
This power of continuing motionless, with the 
lifted head projecting forwards, for an indefinite 
time, is one of the most wonderful of the serpent’s 
muscular feats, and is of the highest importance 
to the animal both when fascinating its victim and 
when mimicking some inanimate object, as, for 
instance, the stem and bud of an aquatic plant; 
here it is only referred to on account of the effect 
it produces on the human mind, as enhancing the 
serpent’s strangeness. In this attitude, with the 
round, unwinking eyes fixed on the beholder’s face, 
the effect may be very curious and uncanny. 
Ernest Glanville, a South African writer, thus 
describes his own experience. When a boy he 
frequently went out into the bush in quest of 
game, and on one of these solitary excursions he 
sat down to rest in the shade of a willow on the 
bank of a shallow stream; sitting there, with 
cheek resting on his hand, he fell into a boyish 
reverie. After some time he became aware in a 
vague way that on the white sandy bottom of the 
stream there was stretched a long black line which 
had not been there at first. He continued for some 
time regarding it without recognising what it was; 
but all at once, with an inward shock, became fully 
conscious that he was looking at a large snake. 
Presently, without apparent motion, so softly and 
silently was it done, the snake reared its head above the 
surface and held it there, erect and still, with gleaming 
eyes fixed on me in question of what I was. It flashed 
upon me then that it would be a good opportunity to test 
the power of the human eye on a snake, and I set myself 
