i88o.] 
Instinct and Mind . 
233 
faculty; and whenever a variation occurs in a particular 
species or variety, each member of its class practises the 
same peculiarities. In some rare cases are found adapta- 
bilities to particular circumstances : not to multiply instances 
may be noted the jackdaw which built its nest in the window- 
ledge of a tower, and piled up sticks to make the basis of 
its nest more stable. The constructive instinct of birds is 
most diversive in character, but the tribal character is 
always maintained. It is the same when the prevision of 
insects is noticed : the water-spider (Naiadese) weaves a 
water-tight cone beneath the water, attaching it to the 
bottom with stays of silk, in order to provide a shelter for 
its young. Its labour would be useless unless the creature 
could empty the cone of the water with which it is filled. 
Walcknaer, who critically observed their habits, says they 
fix a globule of air to a hair of their bodies, and descend 
with it to the nest and eject it beneath the cone, by which 
means they force back the water, and fill it with “respirable 
gas.” “ The spider comes to the surface of the stream, 
takes a bubble of air under its abdomen,” and carries it 
beneath the water : the voyages are repeated till the bell is 
completely filled with air. Thus we may say Nature in- 
vented the diving-bell; but .man, the copyist, has not 
equalled the inventor : the insect begins and completes its 
dwelling below the water, and afterwards expels the water, 
replacing it with air. In all animal mechanics the principle 
is the same ; it is the whole tribe or species which possess 
and practice the aptitude to which culture could not add; 
the instinct is the inheritance of the particular tribe or 
variety. In all this there is no individualism ; we find only 
a class distinction. The sassafras bombyx deposits its eggs 
on the leaf of the tree, and then interweaves the leaf-stalk 
with the stem of the tree so strongly that the leaf, laden 
with its living freight, remains on the tree, braving the 
blasts of the winter. This process could be conceived to be 
a reasoned abstraction (although related to the affectional 
instinct), but the same fatality as an adverse argument 
exists — the distinction is tribal. The larva of the ant-lion 
in dry fine sand hollows a funnel-like inverted cone, and 
makes the slopes so regular, and at such an inclination, 
that they cannot be climbed : the larva buries itself at the 
bottom of the trap ; an insect stumbling on the edge of the 
pit falls into it ; the yielding sand carries it to the foe in 
waiting, and, more, the creature ejects from its lair the 
debris of its feasts, — using its head by way of a catapult, it 
launches the refuse far from the snare : still the instinct is 
