Essays on the Microscope: Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc.Adams, George
Science
Essays on the Microscope: Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc.
Adams, George
Insects -- Early works to 1800; Microscopy -- Early works to 1800
We may now be permitted to make a few reflections on this singular
animal. On considering the various properties that have been already
described, many particulars will be found in them that are very
analogous to others that are continually carrying on around us; we
perceive that there is a successive unfolding of new parts. In every
organized frame there is a continual effort to extend its sphere of
action, and enlarge the operation of that portion of life which is
communicated to it. This gradual evolution requires a secret and curious
mechanism, to regulate and modify by re-action the continued conatus of
the forming principle within it. The polype is an organized whole, of
which each part, each molecule, each atom, tends to produce another; it
is, if we may so speak, one entire ovary, a compound of germ, or seed.
In cutting a polype to pieces, the nourishing juices, which would have
been employed in supporting the whole, are made to act upon each
portion.
When a polype is divided longitudinally, it forms two half tubes; the
opposite edges of these approach, and in a very short time form a
perfect tube. The sides are made to touch each other by certain motions
and contractions of the piece; but as soon as the edges come in contact,
a slight adhesion takes place, the corresponding vessels unite, and new
ones are unfolded, as in a vegetable graft; by these means the points of
connection and cohesion are multiplied, the motion of the fluids is
re-established, and with them the vital œconomy. This is performed with
more rapidity than in vegetables, because the polype is nearly
gelatinous, and its parts are extremely ductile; this ductility is
supported and preserved by the element which it inhabits. The same
reasoning applies equally to explain the formation of so many heads to a
polype, as constitute it a real hydra.
A new polype is formed out of small portions or fragments, in a very
different manner, the operations in nature being always varied,
according as the circumstances differ; each fragment is puffed up, the
skin separated, and an empty space is formed within it; this part is to
become the stomach of the rising polype, which soon sends forth arms,
and is formed to the perfection proper to its kind. We learn from this
instance that the skin of the polype is not so simple as was at first
imagined; for we find it dividing itself into two membranes, and forming
thereby a cavity fit to perform all the functions of a stomach; but why
these membranes are separated in the small portions, and not in the
larger, we cannot tell; but though we are ignorant of this, and many
more circumstances relative to the re-production of these little
animals, yet the foregoing facts enable us to understand better the
nature of the existence of these polypes which have been turned inside
out.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account