Peckham—Spiders of the Family AUidae. 181 
Table II .—Showing the Distribution of Spiders, by Families— Cont. 
Family. 
Regions. 
Ethi¬ 
opian. 
Oriental. 
Palae- 
arctic. 
Austra¬ 
lian. 
Nearctic. 
Neo¬ 
tropical. 
Senoculidae. 
Oxyopidae. 
Attidae. 
Ammoxenidae. 
.... 
.... 
The distribution of spiders must depend very largely upon 
their habit of ballooning. On warm breezy days in the fall 
of the year, the young of many species may be seen, often in 
immense numbers, poised upon somje elevated spot, a post, a 
rock, or perhaps a tall blade of grass, with spinnerets uplifted. 
In this position threads of gossamer are emitted and are 
drawn out to a great length by the wind, which finally lifts 
them and bears them away to fresh fields. TWo cases have 
been observed which show that, under favorable conditions, 
spiders may be carried several hundred miles. Darwin notes 
that at a distance of sixty miles from land, while the “Beagle” 
was sailing before a steady, light breeze', the rigging was cow 
ered with numbers of small spiders with their webs; 1 and 
Capt. George H. Dodge, when more than two hundred miles 
from land, once found the masts and rigging of his vessel 
covered with innumerable little ballooning spiders. 2 In this 
instance the voyagers, after a pause, disappeared as they had 
come, on the wings of the wind. These migrations occasionally 
take place on a scale of astonishing magnitude. Quantities of 
wasted webs,—filaments snapped off by the breeze before the 
spider succeeds in mounting, are carried high into the air, 
where they become tangled together in flocculent masses, to fall 
again to the earth in showers of gossamer. One of these is 
described by Gilbert White, 3 as covering eight miles of terri- 
1 Voyage of the Beagle, Vol. Ill, p. 187. 
2 McCook, American Spiders and their Spinning-work. Vol. II, p. 273. 
3 Natural History of Selbourne, Letter LXV. 
