t me in mind of a certain creature I
have seen in _London_, that was brought out of _America_, which would very
firmly suspend it self by the tail, with the head downwards, and was said
to keep in that posture, with her young ones in her false belly, which is a
Purse, provided by Nature for the production, nutrition, and preservation
of her young ones, which is described by _Piso_ in the 24. Chapter of the
fifth Book of his Natural History of _Brasil_.

The motion of it was with the tail forwards, drawing its self backwards, by
the striking to and fro of that tuft which grew out of one of the stumps of
its tail. It had another motion, which was more sutable to that of other
creatures, and that is, with the head forward; for by the moving of his
chaps (if I may so call the parts of his mouth) it was able to move it self
downwards very gently towards the bottom, and did, as 'twere, eat up its
way through the water.

But that which was most observable in this creature, was, its Metamorphosis
or change; for having kept several of these Animals in a Glass of
Rain-water, in which they were produc'd, I found, after about a fortnight
or three weeks keeping, that several of them flew away in Gnats, leaving
their husks behind them in the water floating under the surface, the place
where these Animals were wont to reside, whil'st they were inhabitants of
the water: this made me more diligently to watch them, to see if I could
find them at the time of their transformation; and not long after, I
observ'd several of them to be changed into an unusual shape, wholly
differing from that they were of before, their head and body being grown
much bigger and deeper, but not broader, and their belly, or hinder part
smaller, and coyl'd, about this great body much of the fashion represented
by the prick'd line in the second _Figure_ of the 27. _Scheme_, the head
and horns now swam uppermost, and the whole bulk of the body seem'd to be
grown much lighter; for when by my frighting of it, it would by frisking
out of its tail (in the manner express'd in the Figure by BC) sink it self
below the surface towards the bottom; the body would more swiftly
re-ascend, then when it was in its former shape.

I still marked its progress from time to time, and found its body still to
grow bigger and bigger, Nature, as it were, fitting and accoutring it for
the lighter Element, of which it was now going to be an inhabitant; for, by
observing one of these with