122 
ANIMAL CURIOSITIES 
Prom these glands exudes a milky and 
poisonous fluid, which, however, is not as a 
rule of a very powerful nature, although 
sufficiently venomous to kill small animals 
or to cause a dog to foam at the mouth. But 
that of a South American species (Dendro- 
bates tinctorius) is so potent in its action that 
the Indians utilize it for the purpose of poison¬ 
ing their spears and arrows, while, moreover, 
it has the curious property if applied to the 
wounds caused by plucking the feathers 
from green Amazon parrots of changing the 
new plumage to a yellow tint. 
Frogs and toads do not possess ribs, but the 
transverse processes of the backbone are so 
well developed that they compensate, to a 
certain extent, for the absence of this feature. 
Owing to this peculiarity the creatures are 
unable to breathe in the normal manner— 
that is to say, by the alternate expansion and 
contraction of the chest, aided by the ribs 
and attached muscles—but do so by what 
may be termed a swallowing or gulping 
process, the closed mouth serving as an air 
reservoir into which the atmosphere is con¬ 
veyed through the nostrils, and afterwards 
forced into the lungs by the action of 
the tongue and the compression of certain 
muscles. 
