XIV PROTECTIVE COLORATION ok 
march along in vast hordes, swarming over and tearing in pieces 
any small animal which lies in their path. They climb over 
intervening obstacles, searching every cranny, and stripping them 
bare of animal life. Insects which attempt to save themselves 
by flight are preyed upon by the birds, which are always to be 
seen hovering above the advancing army. The spider’s only 
resource is to hang from its thread in mid-air beneath the branch 
over which the ants are swarming, for the spider line is imprae- 
ticable to the ant. Belt ' has observed a spider escape the general 
destruction by this means. 
Protective Coloration.—Examples are numerous in which 
the spider relies upon the inconspicuousness not of its nest, but 
of itself, to escape its natural foes. Its general hues and 
markings are either such as to render it not readily distinguish- 
able among its ordinary surroundings, or the principle has been 
carried still further, and a special object has been “ mimicked ” 
with more or less fidelity. 
This country is not rich in the more striking mimetic forms, 
but the observer cannot fail to notice a very general correspond- 
ence in hue between the spiders of various habits of hfe and their 
environment. Those which run on the ground are usually dull- 
coloured ; tree-living species affect grey and green tints, and those 
which hunt their food amongst sand and stones are frequently so 
mottled with yellow, red, and grey, that they can scarcely be 
recognised except when in motion. 
A few of our indigenous species may be mentioned as espe- 
cially protected by their colour and conformation. T'ibellus oblongus 
is a straw-coloured spider with an elongated body, which lives 
among dry grass and rushes. When alarmed it clings closely to 
a dry stem, remains motionless, and escapes observation by its 
peculiarity of colour and shape. JMiswmena vatia, another of 
the Thomisidae or Crab-spiders, approximates in colour to the 
flowers in which it is accustomed to lurk on the watch for prey. 
It is of a variable hue, generally yellow or pink, and some 
observers believe that they have seen it gently waving its anterior 
legs in a way which made them easily mistaken for the stamens 
of the flower stirred by the breeze. Its purpose appears to be to 
deceive, not its enemies, but its victims. It seems to be partial 
to the blooms of the great mullein (Verbascum thapsus), and 
1 The Naturalist in Nicaragua, p. 19. 
