The history of silk, cotton, linen, wool, and other fibrous ... - Cd3wd.com

178 CULTIVATION AND MANUFACTURE OF SILK.
easily discerned, fastened to the place : this operation was again
resumed, until all the threads were in sufficient numlDer : one
fibre being produced at each movement of the tongue.
The old threads were found to differ materially from those
newly spun, the latter being whiter, more glossy, and transparent
than the former, and it was thence discovered that it was
not the office of the tongue to transfer the old threads one by
one to the new spots where they were fixed, which course M.
Reaumur had thought was pursued. The old threads once
severed from the spot to which they had been originally fixed
were seen to be useless, and that every fibre employed by the
fish to secure itself in a new position was produced at the time
required ; and, in short, that nature had endowed some fish, as
well as land insects, with the power of spinning threads, as
their natural wants and instincts demanded. This fact was ia-
controvertibly established by cutting away, as close to the body
as they could with safety be separated, the old threads, which
were always replaced by others in a space of time as short us
was employed by other muscles not so deprived.
" The pinna and its cancer friend" have on more than one
occasion been made subjects for poetry. There is doubtless
some foundation for the fact of the mutual alliance between
yet some
these aquatic friends which has been thus celebrated ;
slight coloring may have been borrowed from the regions of
fancy wherewith to adorn the verse, and even the prose history
of their attachment may be exposed to a similar objection.
The scuttle-fish, a native of the same seas with the pinna, is
its deadly foe, and would quickly destroy it, were it not for its
faithful ally. In common with all the same species, the pinna is
destitute of the organs of sight, and could not, therefore, unassisted,
be aware of the vicinity of its dangerous enemy. A
^mall animal of the crab kind, itself deprived of a covering, but
extremely quick-sighted, takes refuge in the shell of the pinna,
whose strong calcareous valves affords a shelter to her guest,
tchile lie makes a return for tins j)rotect ion by going forth in
search of prey. At these intervals tlie pinna opens lier valves
to afford him egress and ingress : if the watchful scuttle-fish
now approach, the crab returns instanter with notice of the