( 74* ) 
more convenient manner n:iay fill the place which they 
: leave in moving. 
Now the Tails of thefe Worms are thickeft next 
their Bodies, and proportionably gow lefs and lefs, tiH 
at laft the very end of all, if the matter in which they 
fwim be thicker than ordinary, efcapes the fight, a- 
greeing, as to their Tails with all forts of Fifhes, and 
the fame is in Land Animals, whofe Tails are propor- 
tioned to their Bignefs, and always grows lefs towards 
the end. 
i Having obferv'd with my Microfcope many of thofe 
Creatures which I took out of the Tefticlesof thePcam, 
a little before the writing of this, I caus'd feveral of 
them to be drawn as follows. 
Fig. 2» DE F (hews one of thefe Worms lying dead, 
without that moifture in which they fwim whilft liv- 
ing 3 in this, as in all the reft, you may obferve that 
the Tail is thickeft next the Body. 
In the Body of the faid Creature at D and E are two 
round Bubbles, which are clearer and more tranfparent 
than the reft of the Body. 
As the Painter had (everal of thefe Worms before his 
eyes at once, I order'd him to draw one of them whofe 
Tail was more curved than the others. Hereupon the 
Painter drew that Worm which is defcrib'd by Fig. §. 
G H I K. He delineated fome parts of the Body which 
do not agree with thofe of Fig. 2. but that ought not 
feem ftrange to us, when we confider that their diffe- 
rent Site or Pofition is fufficient to make them appear 
different 5 for if fometimes the Belly be opposed to our 
fight, and fometimes the Back or Sides, their Intra ils, 
which are covered with a thin clear Membrane in their 
Bodies, muft needs appear of a different Contexture 5 lb 
that in fbort the fame Worm might be reprefented to 
^ur fight in 18 or 20 feveral poftnres. 
^AmoDgft 
