( 9®2 ) 
I remento i that having heretofore obferv*d[ the Brain of a 
Duck^ I then judged, that they were caufed only by the clofc u- 
nion, which the globuls (of which I then thought the whole 
Brain was made up) had to one another , and which did change 
into threds by a little ftretching. But continuing ray Obferva- 
lions for almoft a whole raonth together, I have feen plainly the 
very great number of exceeding Hnall veins running through the 
Brain,- of which I could not at firft aflure my felf in che Brains 
of Beads, that they were indeed Veins , becaufe they are diffi- 
cult to difcern : But coming to obferve the Brains of Cod fifh^ 
I- very plainly faw thofe many veflels or veins, which were very 
clear, and withal very many throughout , diffeminacing them- 
felvesby their fmall branchings, and being 15 or 20 times finer 
than a fingle thred of a Silkworm. Thefe fmall veflTels or ve ins 
I have feen in great nnmbers in no greater quantity of the brain 
thaa might equal a grain of Sand : Befides, I faw veflels filled 
with blood or appearing red ; as alio veflels that had the thick- 
nefsof a fingle thred of a Silk- worm, accompanied with great 
cjearnefs. 
Purfuing thefe my Obfer vat ions about the Brains of Beafts, 1 
was abk very plainly to reprefent to my felf the veflels above 
difcourfed of; and I could not without great admiration behold 
ihem, partly byreafonof their great number, partly of their 
extraordinary fublety^fo that I muft needs fay, that if one blood- 
globul, I mean of thofe that make the blood red, were divided 
into eight parts, and were of a ftiff fubftance, it could not pafs 
any of thefe fmall veflels. And the oftner I repeated my obfer- 
vations, the plainer I could fee thofe manifold little veflels with 
their ramufcles, which were all very feeble, and by theleafl: 
touch broke afunder.. 
Among the faid globuls, of which in part the Brain conflfts, 
I have feen Blood -globuls, which may very plainly be difcern'd 
from the Brain-globuls , efpecially by the perfeft roundnefs 
which the blood globuls had. Thefe blood-globuls, I imagined, 
came out of the fanguineous veflels,which run through the Brain, 
and had been cut in pieces by the Knife. 
Between the Cortical and Medullar pnt of the Brain lean 
fee little or no difference, efpecially when 1 reprefent them be- 
fore me very thin : Only this I noted^ that the I tf 1( veins or vef 
(els which ran through the CV/ejf^ v\ere ofacarK and brown 
CO i our,. 
