SABELLA. 177 
the body ; another is considerably prolonged, so as to afford a safe re- 
treat in times of danger. The architect of a third seems to persist in 
advancing the fabric as long as it can procure materials. It never 
wearies of working, thus sharing the nature of the Jerebella, of which 
more hereafter. 
Night is the chief season of architectural labour, though perfect 
idleness never leaves the day unoccupied. 
By means of the tentacular organs, and the cleft im the anterior 
part, grains of sand are selected and adapted to the precise spot, where 
glutinous matter secures them to the tube for sheltering its otherwise 
defenceless tenant. 
Among the most interesting instincts displayed in animal life, are 
those whereby weak and unresisting creatures shew their gift from 
Nature in rearing the means of self-protection. 
I know not that an individual animal, if adult, is capable of found- 
ing a tube, but rapid advances extend that which is already in progress, 
and in repairing the breaches of those which are injured. 
This may be readily witnessed by the inquisitive observer. 
On one occasion the dwellings of a colony of Sabella had been acci- 
dentally impaired, so as to leave them only about half an inch in height ; 
but on a supply of sand, it became soon evident that a member of the 
community, more active than the rest, had constructed a tube not less 
than two inches and ahalf inlength. In endeavouring to ascertain their 
preference for particular substances, I supplied this specimen, among 
others, with brick dust and pounded glass. Only a few particles of each 
being used in a week, shewed them to be unsuitable, therefore 1 removed 
the architects to a bed of sand. The active Sabella did not now relax 
in its industry. Sometime afterwards it was accidentally buried during 
weeks among mud, which it survived with impunity ; and it next em- 
ployed itself in extending its cylinder still more and more with sand and 
shelly fragments. 
As the habits of such creatures may be rendered subservient to the 
curiosity of the observer, who desires a distinct view of their operations 
while unrestrained in their own dwellings, he must watch the time when 
Z 
