 —aer 
HORIZONTAL SNARES AND DOMED ORBS. 159 
they precipitate themselves from their snares to the ground. I prepared 
to draw my specimen upward by her dragline, feeling sure that I would 
certainly capture her, when, to my amazement, she threw herself upon 
the surface of the water, a distance of eight or ten feet. I looked to see 
her drown, or at least to be swept away through the open sluice gate by 
the fast rushing stream. Neither of these things happened. The 
moment our Stilt spider struck the water she reached upward 
one hind leg, clasped the dragline in her claw, and began to 
scurry over the mill race toward the shore. 
I watched the movement with exceeding interest, and was delighted to 
see the adventurer reach her destination. (See Fig. 151, right hand figure.) 
The dragline, partly by its natural elas- 
ticity, but also because the spider prob- 
ably reeled out thread as she traveled, 
continued to stretch as the spider moved 
toward the shore. It thus held her firmly 
anchored to the surface of the plank to 
which her dragline was attached, so that 
the force of the current, thus counteracted, 
did not sweep her through the open sluice 
over the shoot. In the meantime her feet 
were kept in motion, and she appeared to 
me to be walking the water in the man- 
ner of certain so-called “ water spiders,” 
belonging to the genera Dolomedes and 
Lycosa of the Citigrades. It certainly is 
an interesting fact in the natural history 
of an orbweaving spider, that it possesses 
a habit so closely resembling one charac- 
teristic of a tribe widely separated from it 
in nearly every other respect. ie ee 
The outspun filaments that serve the 
spider for navigating the air are also’ utilized for propulsion over the 
water. In one case they serve as a balloon, in the other as a 
sail. This discovery was made on a pleasant October day while 
walking along the shore of Deal Lake, Asbury Park, New Jer- 
sey... I stopped before a clump of tall grass that grew upon a little 
tongue of land that jutted into the lake, in order to shake down from the 
foliage any spiders who might for the time be domiciled thereon. The 
especial object of my search was water frequenting species, particularly 
the common Dolomede (Dolomedes sexpunctatus), whose mode of run- 
A Spider 
Sailor. 
Navigat- 
ing Water 
‘October 21st, 1881. I believe that I have the honor to be the first person who ob- 
served, or at least announced, this interesting behavior. See a note published in “The 
Continent,” Philadelphia, August 2d, 1882. 
