FACULTIES OF THE MIND. 255 
tected state during all the stages of his existence. Others, 
(as the Sabelle,) construct a covermg of particles of sand 
cemented together, increasmg the diameter of the tube with 
the corresponding increase of the size of the body. Those 
animals which construct a permanent covering with which 
they are connected, in every period of life, are all inhabi- 
tants of the water. Man is the only animal endowed with 
this instinct, that inhabits the land. Parental tenderness 
supplies his wants in the first instance, and afterwards he 
is guided by this active power, regulated by habit, and the 
principle of imitation. 
As subordinate to this desire, we may here take notice 
of the Habitations of Animals, mto which they retire at 
particular intervals. 
The most common display of this instinctive power in the 
formation of a dwelling, may be observed in those animals 
which burrow in the earth. These form their holes with 
their jaws, as many insects, or with their feet, as quadru- 
peds and some birds. The retreat sometimes consists of a 
single apartment, while others excavate several chambers, 
leaving the walls without a covermg, or giving them a coat 
of plaster to prevent them from crumbling down. In many 
cases, there is only one entry, while others make use of two 
or more. In the arrangement of the entry, this instinct 
displays its extraordinary powers. Sometimes the en- 
trance, as in the case of the otter and pole-cat, opens into 
a thicket, or under the cover of a hanging bank. In 
other cases, as that of a spider, termed by LarrE1tiE 
Mygale cementaria, the entrance is closed by a door 
formed of particles of earth cemented by silken fibres, and. 
closely resembling the surrounding ground. This door, or 
rather valve, is united by a silken hinge to the entrance, at 
its upper side, and so balanced, that when pushed up, it 
shuts again with its own weight. 
