288 
Peckham—The Sense of Sight in Spiders. 
search after them patient and persistent, but always unavail¬ 
ing until they touched the cocoon. 12 
We have also made experiments to determine what the pow¬ 
ers of vision are in the Lycosidse. When at liberty, these spi¬ 
ders rush along so rapidly and seize their prey so suddenly that 
it is very hard to say at what distance they perceive an object. 
Even in confinement they are more difficult subjects than At- 
tidse. 
A male of Lycosa nidicola was placed in a narrow case of col¬ 
ored glass made up of plates each of which was four inches wide. 
The case was sixteen inches long. The spider was standing at 
one end when we put a green grasshopper in at the other. 
After a time he began to move down the case. When eight 
inches away from the grasshopper he appeared to see it, mak¬ 
ing a change in his movements, but whether this inference was 
correct or not he certainly saw it at four inches, since when 
separated from it by the width of one of the plates he leaped upon 
it and began to eat it. This experiment was repeated with three 
other spiders of the same species and all jumped upon grass¬ 
hoppers or small spiders at from three to four inches; while Ly¬ 
cosa nigroventris leaped upon its prey when two inches away. 
Further evidence concerning the powers of sight in the Ly- 
cosidee is given by W. H. Hudson in his very interesting work 
on the La Plata. He says: 
“The king of the spiders on the pampas is, however, not a 
Mygale, but a Lycosa of extraordinary size, light grey in colour, 
with a black ring round its middle. It is active and swift, and 
irritable to such a degree that one can scarcely help thinking 
that in this species nature has overshot her mark. When a 
person passes near one—say, within three or four yards of its 
lurking place—it starts up and gives chase, and will often fol¬ 
low for a distance of thirty or forty yards. I came once very 
nearly being bitten by one of these savage creatures. Riding 
at an easy trot over the dry grass, I suddenly observed a spider 
pursuing me, leaping swiftly along and keeping up with my 
beast. I aimed a blow with my whip, and the point of the lash 
12 For a more complete discussion of this subject see our paper, Mental 
Powers of Spiders, Journal of Morphology, Vol. I, p. 399. 
