( 12 9 ) 
IL Obferyations upon the Membranes enclojtn g the 
Fafciculi of Fibres, into which a Mujcle is di- 
vided. !By Mr. Leeuwenhoek ? F. R. S. 
Tranflated by Dr. Sprengell, F. S. 
Jan. 9. 1720. 
S Oinetime ago I mifs’d a fmall piece of Flefh, 
which I had left Handing before a Microfcope, and 
endeavouring to procure fuch another, I cut off fe- 
veral thin llices from a piece of Beef j in doing 
which, whenever I cut the flefhy Fibres thro’ tranf- 
verhy, I could plainly difeover the Membrane, as it 
is commonly call’d, which runs between and enve- 
lopes the flefhy Fibres, and efpecially the larger 
Fafciculi of them, as they run lengthwife along the 
Mufcle. Between thefe Fafciculi the Membrane is 
of a confiderable thicknefs, but fpreads out every 
way into Ramifications exceedingly fmall. I had 
obferv’d fome Weeks before, that this Membrane 
was compofed of an inconceivable number of very 
fmall VeiTels, which were plainly to be drfeern’d not 
only where the Membrane appear’d of fome confide- 
rable breadth, but even where it was not fo broad as 
a fingle Mufcular Fibre ^ but how far this held, I 
could not determine, forafmuch as thefe fmall Rami- 
fications of the Membrane, did again fpread them- 
felves into other Ramifications fo exceedingly fine, 
efpecially where they enclofed the fingle Mufcular 
^ Fibres, 
