184 The Naturalist in La Plata. 
with a curious modification of structure abounds on 
the pampas. The long leg of this spider is no 
thicker than a bristle from a pig’s back, but at the 
extremity it is flattened and broad, giving it a 
striking resemblance to an oar. ‘These spiders are 
only found in herbage overhanging the borders of 
streams: they are very numerous, and, having a 
pugnacious temper, are incessantly quarrelling ; and 
it frequently happens that in these encounters, or 
where they are pursuing each other through the 
leaves, they drop into the water below. I believe, 
in fact, that they often drop themselves purposely 
into it as the readiest means of escape when hard 
pressed. When this happens, the advantage of the 
modified structure of the legs is seen. The fallen 
spider, sitting boat-like on the surface, throws out 
its long legs, and, dipping the broad ends into the 
water, literally rows itself rapidly to land. 
The gossamer-spider, most spiritualofliving things, 
of which there are numerous species, some extremely 
beautiful in colouring and markings, is the most 
numerous of our spiders. Only when the declining 
sun flings a broad track of shiny silver light on the 
plain does one get some faint conception of the un- 
numbered millions of these buoyant little creatures 
busy weaving their gauzy veil over the earth and 
floating unseen, like an ethereal vital dust, in the 
atmosphere. 
This spider carries within its diminutive abdomen 
a secret which will possibly serve to vex subtle 
intellects for a long time to come; for it is hard 
to believe that merely by mechanical force, even aided 
by currents of air, a creature half as big as a barley 
