XIV MIMICRY B73 
Such resemblances, obvious enough in nature, and heightened 
by the behaviour of the mimetic form, are often by no means 
striking in the cabinet. In some American species of spiders, 
however, imitation of the ant has passed beyond the stage of a 
general resemblance as regards size and colour and method of pro- 
eression. The head of the ant is well marked off from the body, 
and the thorax is frequently divided into distinct regions. These 
peculiarities are imitated by constrictions in the cephalothorax 
of mimetic spiders. The resemblance, moreover, is much increased 
by their habit of using but six legs for locomotion, and carrying the 
second pair as ants do their antennae. The best known examples 
of these spiders are Synageles picata and Synemosyna formica (see 
Fig. 215, C, p. 420), and even more striking resemblances have been 
observed among some undescribed South American species. 
The object of such mimicry seems to vary in different cases. 
Sometimes the spider preys upon the ant which it resembles. 
Sometimes, again, by its disguise, 1t escapes the notice of the ant 
which would otherwise feed upon it. More often spider and ant 
are neutral as regards each other, but, under cover of its resemblance, 
the Arachnid is enabled to approach an unsuspecting victim to 
which the ant is not a terror. Again, the unpleasantly acid taste 
of ants is unpalatable to most birds, though not to all, and the 
increased danger from specially ant-eating birds may be more than 
counterbalanced by the immunity they acquire from other birds. 
There is quite a large class of Spiders of nocturnal habits, whose 
only precaution by day is to sit perfectly still and be mistaken 
for something else. We have referred to the adaptation in 
colour of our English species, Wiswmena vatia, to the flowers in 
which it lies in wait for prey. Bates’ mentions exotic examples 
of the same family which mimic flower-buds in the axils of 
leaves. Herbert Smith says of a spider which sits upon a leaf 
waiting for prey: “The pink three-lobed body appears just like 
a withered flower that might have fallen from the tree above; 
to the flies, no doubt, the deception is increased by the strong 
sweet odour, like jasmine.” 
Trimen * describes a Cape Town species which is of the exact 
rose-red of the flower of the oleander. “To more effectually 
conceal it, the palpi, top of the cephalothorax, and four lateral 
1 Naturalist on the Amazon, 1873, p. 54. 
2 Protective Resemblances and Mimicry in Animals, 1873, p. 4. 
