( 14 ° ) 
I could plainly fee, that how fmall foever thefe Fibres 
were, they were {till vafcular, for I could fee the 
light thro* the apertures of thefe Velfels, as I had 
done before in thofe of a Whale } but if I happen’d 
to cut the fibres never fo little obliquely, inftead 
of cutting them dire&ly acrofs their length, the 
light was not to be feen thro* them. 
1 had in a Drawer the hind Quarter of a Moufe, 
which had kin there fome Years } from the largeft 
Mufcle of which I cut off tranfverfly fome fmall 
Slices, as thin as poffibly I could. Then placing thefe 
before my Microfcope, I not only faw, that the car- 
nous Fibres were of the fame thicknefs with thofe of 
an Ox, but befides I could fee the apertures of the 
Veffeis com poling the carnous Fibres, as plainly as 
in the fleih of a Whale. The Veffeis in the Mufcular 
Fibres of a Whale, are indeed fix times more in 
number, than in thofe of an Ox, or a Moufe, but 
then the Fibre of a Whale is alfo fix times as thick 
as the other. 
Hereupon I confider’d after what manner the 
Veffeis, of which the mufcular Fibres moftly confift, 
receiv’d their nourifhment from the Veffeis of the 
Membranes, fince the mufcular Fibres, when they 
are at reft, have many alternate corrugations, by 
which I judged, that the Veffeis in the Fibres muft have 
their fides prefs’d together, and their cavities clofed up. 
But if we call to mind, that in walking a Man may 
move both his Feet above 3600 times in an Hour, 
(for he may make two fteps in the time of one pulfa* 
tion of the Artery,) and. that in that fpace of an Hour, 
the mufcular Fibres muft be. fo many times exten- 
ded and contracted, and will therefore require great 
Supplies-^ we {hall likewife find that this is fuffi- 
ciently 
