lying on the ground dozens could be shaken; but so rapidly had they
devoured, by the trained army of persecutors, that in spring it was hard
to find a survivor, even in the barns and houses. The fact that species
tend to increase in a geometrical ratio makes these great and sudden
changes frequent in many regions of the earth; but it is not often they
present themselves so vividly as in the foregoing instance, for here,
scene after scene in one of Nature's silent passionless tragedies opens
before us, countless myriads of highly organized beings rising into
existence only to perish almost immediately, scarcely a hard-pressed
remnant remaining after the great reaction to continue the species.




CHAPTER IV.

SOME CURIOUS ANIMAL WEAPONS.


Strictly speaking, the only weapons of vertebrates are teeth, claws,
horns, and spurs. Horns belong only to the ruminants, and the spur is a
rare weapon. There are also many animals in which teeth and claws are
not suited to inflict injury, or in which the proper instincts and
courage to use and develop them are wanted; and these would seem, to be
in a very defenceless condition. Defenceless they are in one sense, but
as a fact they are no worse off than the well-armed species, having
either a protective colouring or a greater swiftness or cunning to
assist them in escaping from their enemies. And there are also many of
these practically toothless and clawless species which have yet been
provided with other organs and means of offence and defence out of