[ 21 ] 
XLV. 
I/?, I divided fome Fibres as minutely as I poflibly 
could, from the Heart of an Ox, from a Part of the 
Diaphragm, from the intercoftal Mufcles, and from 
a Rump of Beef 5 all winch were boiled to fuch a 
Degree of Tendernefs, that we feparated fome Fi- 
bres with the Point of a Needle, which were not 
vifible till placed under the Microfcope,. and even 
then they did not appear bigger than Hairs, though 
others, which looked like Hairs to the naked Eye, 
were magnified to the Size of Wheat-Straws. All 
thefe feem'd to be Fafcicles of continued Tubes, as 
far as we could view them, without any Partitions 
or Cells. 
XLVL 
2 dly y Upon rending a Mufcle, which was taken 
from a Knuckle of Veal, and boil'd for four or five 
Hours, feveral of the tranfverfe, as well as longitu- 
dinal Fibres appear'd very diftin&ly* which being 
placed under the Microfcope, and having a ftrong 
focal Light caft upon them by means of a Florence 
Flask fill'd with Water, they feem'd to be fhrunk 
up, either by being boil'd fo long, or by being ex- 
pofed to the Air,, fo that their Surfaces feemed to be 
unequal and corrugated 5 which is what Mr. Leeu- 
wenhoek * fays deceived him at firft, fo as to make 
him 
* Anatom, & Contempt, p, 43, 
